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How to Install the Network License Version of OpticStudio

Alison Yates & Alissa Wilczynski
Installation and Troubleshooting
Frequently Asked Questions
Hardware Key
First Time Users
Network server configuration


NOTE: Before continuing this article, you should be certain that you have a softkey or red USB license.


Prior to October 2016, Zemax sold black network USB dongles for network licenses. If you have one of these, please visit this page for install instructions.
Please note that the network softkey or red USB key is worth the full value of the software. We recommend that you insure the network key for its full replacement value, and that the keyserver machine be kept in a secure room. If the key is lost or stolen, it will not be replaced without payment of the full purchase price. You may see details of our policy here

Preparing to Install

Before installing the software, there are some simple concepts you must understand. The network license key is installed on a machine called the keyserver. This machine hosts the key and the software that makes the key visible over your local area network (LAN).

The keyserver can be any machine on the network. It does not need to run a server operating system, like Windows Server. It simply needs to run Windows 7 (or Windows Server 2008 R2 SP1) or newer and be visible on the network to all the machines that will want to use network licenses. 

Client machines are the machines that will run OpticStudio and use the network license. The client machines must be able to ping the keyserver in order for network operation to work.

Tip: You cannot run multiple users of OpticStudio on the key server itself or multiple users on a single client machine. The licensing is designed to assign one network seat to each client computer. See the FAQ at the end of this article. 

A few words on license types. OpticStudio network licenses make it easy to receive support renewal updates as they only have to be applied on the server machine. This also means the seats can be shared among a team without using transfer codes or trying to keep track of physical USB dongles for each user.

The Red USB network key has the licensing information embedded in it. The softkey has no physical unit -- the license itself is attached to the keyserver computer through software. The features of both types are the same, except for license seat check out (to use a license seat on a client when offline or to dedicate a seat to a user for a period of time) is available for Softkey licenses, but not the Red USB license.

For both license types, Zemax uses the Gemalto (formerly Safenet) Sentinel LDK license technology, and communicates on port 1947 on your network.  We highly recommend using this port if possible, as changing it has some side effects and requires each client machine to change the port manually as well. If you would like details on changing this port, see the Frequently Asked Questions section of this article. 

Installing on the Keyserver Machine 

Part 1 -  Software Installation and Activation 

Note: You must be logged in with administrator rights on the key server machine. 

1 - 
For installations on machines without internet access, you will need to first download and install the .NET Framework from Microsoft., unless it is installed already. Note that the Windows 10 Anniversary update and Windows Server 2016 already include this. As of July 2018, the minimum .NET version required is 4.6.2. Then you may proceed to step 2 and install the Zemax License Manager.

2 - Navigate to the OpticStudio Downloads page. Open the Resource Files section. Download and launch the Zemax License Manager (ZLM) installer. This application will allow you to view, activate, and update your license information. This installer package includes everything you need to install and manage a softkey or red USB license on a server. You may accept the default options, or choose an installation folder. 

3. Activate your license.

If you have a Red USB license key: 

  • After the license manager installation is complete, you may simply plug in your Red USB dongle. The key is driverless, so Windows should automatically install the device and the key key should light up with a red light. If the key does not light up, unplug the key, and restart the computer. Plug it back in. If it still will not light up, you may need to refer to the "Repairing the Softkey Runtime" section of How to Troubleshoot Softkey License Issues. Move to step 4.  

If you have a Softkey license:

  • Your server is connected to the internet: You should have received an activation code from the Zemax Sales Team. Open the Start menu and launch the Zemax License Manager. Select the “New key” tab along the left, input your activation code, and click "Apply License". If the activation generates an error message, restart the computer and try activating again. If it still does not activate, refer to the "Repairing the Softkey Runtime" section of How to Troubleshoot Softkey License Issues. Once activated, move to step 4 to complete the server configuration
  • Your server is not connected to the internet: please visit this article for instructions to activate your softkey license offline. Then come back to this article and move to step 4 to complete the server configuration.

After activating your softkey, we recommend reading  How to Protect and Prevent Loss of your Softkey License. It gives details on how softkey licenses are locked to the machine, tips to avoid losing it, backing it up, and our policy on lost keys.

The "New Key" screen for activating a softkey license:


4. Verify your license is installed and working. Open the Zemax License Manager and click the "License Information" tab. It should look something like this. Verify the support expiration and number of license seats matches the activation email or purchase order. 


Part 2 - Check or open the Windows Firewall

Normally the installation process opens the Windows firewall for you automatically. This section will tell you how to verify that it is configured.properly.

1. Open the Windows Firewall settings by clicking the Windows Start button and searching for the word Firewall.
2. Click the Windows Firewall app.
3. Click "Allow an app or feature through Windows Firewall". 

4. Check the list of applications. Check if  “License Manageror "Sentinel License Manager" is already on the list.

  • If you do not see one of the above apps, move down to step 5 of this process to add the license manager to the list.
  • If the License Manager is on the list, check that just Private and Domain (if the machine is joined to a domain) is selected. The Public network option normally does not need to be checked, as that can leave your network open to external instrusion. Then you can move to the next section of this article: Part 3 - Configure server settings and security


5. Click "Allow another app". If "Allow another app" is greyed out, you need to click the "Change settings" button first to enable it..

6. Click "Browse" and open the C:\Windows\system32 folder.
7. Select the HASPLMS.EXE.file from the list and click Open

9. License Manager or Sentinel License Manager will appear on the "Add an app" screen. Click the "Add" button to add the "License manager" to list of exceptions. 

10. The check boxes next to "License Manager" specify which type of network includes this exception. Check that just Private and Domain (if the machine is joined to a domain) is selected. The Public network option normally does not need to be checked, as that can leave your network open to external instrusion.

11. Make sure port 1947 is not blocked on your network firewall both for UDP and TCP, and that you can "ping" the IP address of the key server machine from other machines. Consult with your IT department if you are not sure.


Part 3 - Configure server settings and security

1. ​Click on "Launch Sentinel Admin Control Center" (ACC) at the top of the Zemax License Manager application.  You should get the below page.

TIP: You can also get to the Admin Control Center by opening a web browser and navigating to http://localhost:1947

If this page does not open, then follow the steps in "Repairing the Softkey Runtime section of "How to Troubleshoot Softkey License Issues". Click the Sentinel Keys link on the left. You should see the license you just activated, identified by the Key ID field (The key id can be found in the Zemax License Manager).

TIP: If you have more than one license displayed for other software , you will identify your Zemax-brand licenses by Vendor #114811.

2. Click on the Configuration link on the left to see all 6 tabs to configure the license manager. You may configure a password to keep others from changing settings, log usage, restrict users / computers from the license, and configure "Detachable licenses" so client machines can use OpticStudio offline. For full details on all of these settings, refer to the Knowledgebase Article "How Do I Monitor and Control Usage of the Network Key?"


You should be done with the server setup! If you have troubles with any of this process, Zemax support is available by phone or email.

Installing on the Client Machine

NOTE: If you are connecting to a server that has a Black USB network key, the below instructions do not apply. For help with a black USB network key on a client machine, refer to the article "Installing OpticStudio with a Black USB Network Hardkey" in the "Installing OpticStudio on the Client Machine" section.

1. Ensure that you are logged in as an administrator on the machine.
2. Download the latest copy of OpticStudio (must be 15.5 or later) from the Downloads page and run the installer following the installation instructions.
3. Launch OpticStudio. If you are located within the same network as your server, OpticStudio will normally automatically locate the network license and open.
4. If you get an error that it cannot find a license key, or land on the Zemax License Manager, you will need to continue to the next section to manually configure the server settings. 


What To Do If the License Is Not Found Automatically

If the key was not found or you are attempting to access a network key from outside the same network the key server is located in (such as via a VPN), follow the configuration steps below to help point the license search toward the network keyserver location. If you are a network administrator and would like to automate this process for several client computers, see this additional article:

1.  Open the Sentinel Admin Control Center on your client machine (where you intend to run OpticStudio).  To do this, you may click the "Launch Admin Control Center" link at the top of the Zemax License Manager, or open a web browser and type in http://localhost:1947.  If this page does not open, then check the article "How to Troubleshoot Softkey License Issues" 

2. Select the Configuration link on the left column under Options.

3. Click the Access to Remote License Managers tab. Make sure Allow access to Remote Licenses is checked.We recommend you also select Aggressive Search for Remote Licenses. 

4. In the Remote License Search Parameters box, input the machine name of the network license server you would like to access. It is not necessary to include http:// in the machine name.  We recommend using the fully qualified domain name such as or rather than just the machine name itself. You may use an IP address as an alternate, or if there is an OpticStudio license on more than one server, you may add additional names to the list. 

Note that Zemax does not know your server information, as we do not host your license. If this is at an educational institution for an optics class, check with the class instructor. If this is at a business or other organization, contact your manager or IT administrator to obtain the the server information.

5. Click "Submit" when done entering the server information. 


6. Click the "Sentinel Keys" link under Options. This will refresh the list of licenses that are available. Note that there may be a delay of ~60 seconds before the key information is updated after submitting in step 5. Once you see the license, you may close this web page, and restart OpticStudio to verify it can use the network license. If you still do not see the license after a few minutes, continue to step 7.

Example of a network license located on a machine called Owner-pc:

7. If the license key is still not found after entering the server information, try these options:
  • Restart the licensing service on the client machine. See the section at the bottom of this article: Addendum: Restarting the Sentinel LDK License Manager Service to fix issues
  • Try using the IP address of the server rather than the machine name in the Remote License Search Parameters section.
  • Verify if you can reach the server's Admin Control Center (ACC) page. For example, If your server's machine name is licenseserver, enter http://licenseserver:1947 instead of http://localhost:1947 at the top of your browser. Note that if you get an error containing "403 Forbidden" that means you can reach the server, but it is simply not configured to allow remote administration. See if you can ping the server name from a Windows command prompt. If either the ping fails or ACC page is not reachable, you will need to verify you have the correct server information and that the server is working. Check with whoever manages the Zemax license server in your organization.
  • If you are logging in to a company network remotely via a VPN connection, your IT department may need to configure the VPN server or firewall to pass through traffic to the license server's IP address (Port 1947). Zemax cannot help you configure your company firewalls.
  • We also recommend verifying that your security software is not blocking access to the license software. Check your security software's logs to see if either the HASP_RT.EXE in the Opticstudio installation folder (such as C:\program files\Zemax OpticStudio), or HASPLMS.exe in C:\windows\system32 has been blocked. Instructions for Mcafee Enterprise is covered in the Frequently Asked Questions section at the bottom of this page 

Using Zemax License Manager on the Client Machine 

Once OpticStudio is open, the Zemax License Manager (In opticStudio under Help > License Manager) can be used to view information on all your Zemax licenses, select which license to use, or check out a seat for use offline. For more details on the ZLM controls and information, you may also refer to the OpticStudio Help in The Help Tab > Information Group > License Manager.

Selecting a license

If more than one license is available in the License Manager (ZLM), you may click click the Set as Default box to always use a particular license when launching OpticStudio.

Tip: If you cannot launch OpticStudio and get a "no key found error" or are left at the "License Information" screen, check the following:
  • First, if you see the license you want to use, check that the number of available seats on the network license is larger than zero. If it is zero, then all the license seats are in use by others. You will need to wait until at least one other person exits OpticStudio.
  • Click Clear default key so OpticStudio will attempt to use any available key.  Otherwise, refer to Troubleshooting your OpticStudio Installation

If you have one of the older Black USB key plugged into the client computer, and would like to use it before any other license type, check Use black USB key.


License Seat Check Out on the Client (softkey network licenses only)

This optional feature will lock a license seat to your machine until the check out period expires, or until you check it back in. The length of time is set by your OpticStudio network keyserver administrator. If you are going to use OpticStudio while connected to the same network the license is hosted on, normally you should not check out a license seat. That will ensure a license seat is available to others when you are not using it. 

The most common use of the check out feature is to use it offline. For example, you normally use OpticStudio on a laptop at work, and want to use OpticStudio at home. Another common scenario is if you need to ensure to have access to a license seat for a period of time to complete a project.

Follow these steps to check out a license seat on a client machine for use offline,

1. Close OpticStudio.
2. Launch the Zemax License Manager (ZLM)
  • For OpticStudio licenses, you can find the Zemax License Manager in Start > All Programs > Zemax OpticStudio.
  • For Lensmechanix licenses, Open Start > All Programs > Lensmechanix > Zemax License Manager.

3. Your network license will be listed with license type "Network" the list and should have a Check Out button. 

TIP: If the Check out button is greyed out and unavailable, look through the list of licenses to ensure you do not already have a license checked out (Look for a license with a line stating Checked out until and a Check In button). If you do not find a checked out license, then your network must use a Red USB dongle, which does not support license check out.

4. Press the Check Out button.

If the check out was successful, an additional entry in the License Manager will appear with the following information about the checked out license seat. The date next to Checked out until is when the license seat will expire and automatically be checked back in to the server. The length of time is set by your network keyserver administrator. 

Tip: If you press the Check Out button on the client and receive an error stating that the check out could not be completed, or "The server administrator has disabled license check out", you need to contact your network administrator and ask them if license check out on the server is enabled, or troubleshoot the issue. Refer them to the following article :How Do I Monitor and Control Usage of the Network Key?

Checked out license:

5. Once the license seat is checked out, the client machine may be disconnected from the network. To return a license seat before it expires, simply press the Check In button. Note that your computer needs to be online and be able to see the key server the license seat was checked out from.

For more details on the ZLM controls and information, you may also refer to the OpticStudio Help in The Help Tab > Information Group > License Manager.


Frequently Asked Questions

Q: Can I have multiple users run OpticStudio on the license key server machine?
A:  OpticStudio network licenses are designed using a client-server model. The key server is intended host the license itself, and the licensing assigns 1 seat per machine. Also, OpticStudio is designed to allow 2 instances of the application at a time. The key server can run a copy of OpticStudio for one user if you wish. Just be aware that using OpticStudio on the server for long optimizations or raytracing may tie up the CPU and may interrupt the license process for client machines. As a workaround to the above, you could install virtualization software such as VMware, then install Windows and OpticStudio within it.This also would allow you to limit RAM and CPU usage.

Q: Can i use my Sentinel Softkey or Red USB license on a machine that already has an existing Sentinel license for other Zemax or third-party products?
A: Yes. We use Sentinel HASP (LDK) licenses. Sentinel RMS or older USB licenses use a different license service so they can co-exist with the LDK installation. Note that if you use Sentinel LDK versions before 7.60 on your server, any user restrictions are applied to all licenses. For details, see the "Users" section of "How Do I Monitor and Control Usage of the Network Key?"

Q: Do I have to worry about losing my softkey on the key server in case of hardware failure, theft, or a reinstall of Windows?
A: Yes. We recommend reading  How to Protect and Prevent Loss of your Softkey License. It gives details on how softkey licenses are locked to the machine, tips to avoid losing it, backing it up, our policy on lost keys, and optional key insurance (ZPA).

Q: What if Port 1947 is in use on my network?
A: Note that the keyserver and clients communicate on port 1947 on your network. This is because that port is not registered to any other known services. However, if that port is in use on your network, we can provide information to change it. Note that you will have to change the port setting on the key server and each client machine that will access the license server. Also, after the change the license will not be visible in the Zemax License Manager (as it can only see licenses on the default port). Contact Zemax support to get instructions to change it and details. Please include your license key serial number (for example L000000) as well.

Q: How do I configure multiple client machines with the server address, so users don't have to enter it themselves?

A: Normally, client machines will find the key server without entering the server name into the settings as long as they are on the same subnet. However, if you want to preconfigure the clients with a specific server name, or other settings, please see this article for details.

Q: In the Zemax License Manager, the there are less than the total number of available seats I expect to see. Why?

A: First, check on the server machine for licenses that have been checked out (detached) as well as open sessions. For instructions, read this link: Viewing user sessions and checked out licenses. If the total number of seats is still not what you expect, this means that the server has not properly released a session after OpticStudio was closed. To resolve this, you can Restart the Sentinel LDK License Manager Service.

Q: I checked out a license seat for use offline. When i restarted my computer, it was no longer available in the Zemax License Manager. What happened?

A: Check the Sentinel Admin Control Center's "About" page on the client, located at this address: http://localhost:1947/_int_/about.html. If the "Runtime Installer" begins with 7.60 then this is the cause of your issue. This is an issue that was discovered with OpticStudio 17.0 through 18.1. The vendor of our softkey licensing software released an update that addressed this issue. It will be included in the next OpticStudio 18 service pack. You may install the updated Sentinel LDK Runtime by following the steps in "License check out issues (Softkeys only)" section of the following article: How to Troubleshoot Softkey License Issues

Q: Client machines will not find the license server, or hang on the OpticStudio "splash screen" indefinitely. What can I do?

A: First, make sure that the firewall exception on the server is configured in step 5 of the server setup instructions above. Once you are sure of that, check the client machine has specified the name of the server in the What To Do If the License Is Not Found Automatically section. If that is done, then your security software may be blocking access to the license software. We have seen both Trend Micro and Mcafee block this. If you use Trend Micro, check it's scan logs to see if either the HASP_RT.EXE in the Opticstudio installation folder (normally C:\program files\Zemax OpticStudio), or HASPLMS.exe in C:\windows\system32 has been blocked. If you use Mcafee Enterprise, it's HIPS (Host Intrusion Prevention System) feature can block this. You can temporarily turn off HIPS to see if this is the case. On the the client machine, perform the following steps: 

Right-click the Mcafee icon in the system tray (by the time displayed at the bottom right). The Mcafee icon is normally a red shield with an M in the center. Navigate the menu to the Disable option.Select Disable HIPS protection. If this works, your IT department can whitelist the hasp_rt.exe process to fix it permanently. This file is located in c:\program files\Zemax OpticStudio.


Addendum: Migrating your network license to a new server

This section provides a recommended procedure to move to a new server with minimal downtime and configuration. Note that if client machines have a checked out license seat at the time the license is moved to the new server, it will not affect them, as the checked-out licenses simply time out automatically.

1. Install the Zemax License Manager software on the new server following the process at the beginning of this article. If you will be transferring a softkey license to the new server, and your old server has a Zemax License Manager dated before Sept 2016, you will want to update it before transferring it. The transfer process has changed in later versions. Alternatively, use the instructions to transfer the license without internet access instead.

2. Copy the HASPLM.INI file from the current server to the new one. This file contains all the server settings from the Admin Control Center (user rules, detachable license settings, password, etc per the article How Do I Monitor and Control Usage of the Network Key?). It is located in C:\Program Files (x86)\Common Files\Aladdin Shared\HASP

3. Transfer the OpticStudio license from the old server to the new one. If using a Red USB license you may simply plug it in. If using a softkey license, follow one of the guides here:
Transferring and Updating a Softkey License (with internet)
Activate, Transfer, or Update a Softkey License On A Machine Without Internet Access

4. Test the license server is working with an an OpticStudio client machine. If you need to test the new license server before moving the license over, you may email They can provide you a 2 week temporary network license you can use. NOTE: you must have an active support agreement to receive a trial license. If moving a softkey license, test the transfer process between servers with the trial license to make sure it works and get used to the process. After you are done with the trial license testing you will want to remove it from the server to prevent users from accidentally using it after it expires. The easiest way to remove the trial license is to just transfer it away and discard the generated transfer code or h2r file.

5. Let the users of OpticStudio know they may need to modify the settings on their client machines with the new server IP address or machine name. You can provide the new server information and a link to the instructions in this article under "What To Do If the License Is Not Found Automatically".  Alternatively you can provide them with a modified HASPLM.INI file with the new server information per the following article: Automate Client Computer Configuration for Softkey and Red USB key Network Installations

Addendum: Restarting the Sentinel LDK License Manager Service to fix issues

This is useful if it's not practical to restart the entire client or server computer, and can be used to fix the following issues:

  • The license server or clients are not able to see the softkey license in the Zemax License Manager 
  • You change a setting on the keyserver and it doesn't take effect even after submitting changes
  • License check out on the client fails even if the detachable license feature is enabled on the server.
  • You need to release license seats from the server that are no longer actually in use, but are not accessible to other users. 

You may either open the Start menu, and search for services.msc, or open Control Panel > System and Security > Administrative Tools > Services and right-click on Sentinel LDK License Manager and select Restart.