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Troubleshooting your OpticStudio Installation

This article explains what to do if you have problems launching OpticStudio.

If you are able to run OpticStudio but have a crash or other problems while using it, refer to the following article:
How to Report a Problem or Possible Bug to Zemax Support

If you experience slow response in graphics windows while running OpticStudio, refer to the following article.
Troubleshooting UI Issues in OpticStudio
If you experience black (or white) windows when using OpticStudio, refer to the following article.
What to Do if the Graphics Windows in OpticStudio are Black


Issue: OpticStudio Requests a License Code
Issue: OpticStudio is unable to find a license key
Error: OpticStudio requires the .NET Framework
Issue: Nothing happens when launching OpticStudio
Error: OpticStudio has stopped working
Issue: OpticStudio hangs at splash screen on startup

Getting help from Zemax


Alison Yates

Installation and Troubleshooting
Frequently Asked Questions
Hardware Key
First Time Users

Issue: OpticStudio Requests a License Code

The first time you run OpticStudio, you may be prompted for a license code, like so:

License Code

If you see this dialog box, your copy of OpticStudio is correctly installed, and the key driver is working properly, you just need a license code to allow OpticStudio to run with your key.  To get a license code, take a screenshot of this dialog box on your screen (e.g. using Alt-Print_Screen, Snipping Tool, or any other screen capture software) and paste it into an email to and one of our global tech support staff will send a license code right away. Please do not call Zemax for a license code. License codes are complex multi-character strings and cannot be reliably given over the phone. Emailing the screenshot of the dialog box to us is the quickest, most error-free way of getting your license code.



Error: OpticStudio is unable to find a license key 


If you get an error saying "Cannot find Zemax Key" there are some steps you can take, depending on the type of license you have.If you are unsure of your license type, this article may help: Identify Your OpticStudio License

For Black Single User USB keys that are plugged into the machine you are installing OpticStudio to (the key number is printed on the key, like 12345) please refer to Troubleshooting License Issues with a Black USB License

For Single User Softkeys, or Red / Green USB keys plugged on the computer you run Opticstudio on, please refer to How To Troubleshoot Softkey License Issues.

If you are trying to reach a network server that uses a Black USB network key, refer to this document in the "Client" section: Installing OpticStudio with a Black USB Network Hardkey.
If you are trying to reach a network server that uses a network softkey licenses or Red USB network key, refer to this document:Troubleshooting When the License Is Not Found" section of "How to Install the Network License Version of OpticStudio."


Error: OpticStudio requires the .NET Framework

If you are installing OpticStudio 16.5 Sp1 or newer, it requires a minimum of .NET 4.6.2. Normally, OpticStudio automatically downloads the required version of the .NET Framework from Microsoft during installation. If your computer was offline during installation of OpticStudio, or you do not have internet access, it would be skipped. You can download a .NET version that does not require Internet access to get around this.

If you just want the minimum required .NET framework, 4.6.2 is available to download here. Be sure your computer meets the minimum requirements.

However, we recommend installing .NET 4.7.2 as it is backwards compatible with 4.6.2 and will be used in future OpticStudio releases. Be sure your computer meets the minimum requirements. It can be obtained from this page:
Note: Do not install the Windows RT version. 

After installing .NET try and launch OpticStudio again. If you are still unable to launch OpticStudio, or get .NET to install, skip to the Getting Help section.

Issue: Nothing happens when launching OpticStudio

If you have no error and nothing is displayed when launching Opticstudio, this is normally due to missing Windows components that OpticStudio requires to run.

Checking for OpticStudio Updates

Before you do anything else, you should check that the version you are trying to install is the latest release. We make significant improvements with each new release, and this is often our first troubleshooting suggestion when users contact Zemax Support. Note that you must be under a current support agreement to obtain the latest version.

Method 1 - Check your Windows version, and Windows Updates 

Supported Operating Systems: System requirements and supported operating systems can be viewed here. Of special note is that Windows 8.0 is no longer supported by OpticStudio 16.5 Sp3 or higher. Windows XP and Vista have also not been supported by OpticStudio since it's release.

Check for Windows Updates on your PC. Install all available updates, including optional updates.  Optional hardware device driver updates and updates to Microsoft software applications (such as Bing and Skype) are not necessary.

Method 2 - Install Windows Updates Required for OpticStudio 16+ 

If you don't want to use Method 1, which can be time-consuming, you can manually install the minimum updates OpticStudio requires from the list below:

Windows 7 / Server 2008 R2
1. OpticStudio 16 and higher requires Service Pack 1. To check, click your Start button, right-click Computer, and then click Properties. The system information page about your computer will open. If it simply says "Windows 7  (edition such as Professional)" below "Windows edition", without anything after it, you do not have any service packs installed. To obtain help installing Service Pack 1, speak to a computer technician or your company's IT department.
2. Install the April 2015 servicing stack update. It is a prerequisite for many applications, and can be downloaded from this link: KB3020369
3. After the servicing stack update is installed, install the Universal C Runtime Update.

Windows 8 and 8.1 / Server 2012 R2
Windows 8.0 is not supported by OpticStudio 16.5 Sp3 or higher. All users of 8.0 can get a free update to 8.1.

1. Install the Windows Servicing Stack Update. For Windows 8 install KB3096053. On Windows 8.1 install KB3021910.
2. Windows 8.1 or Windows Server 2012 R2 also require the April 2014 update rollup.
3. After the above updates are installed, install the Windows 8.0 Universal C Runtime Update, or Windows 8.1 Universal C Runtime Update

Windows 10

For OpticStudio 16.0 - 16.5 - Windows 10 already contains all required updates. 
For OpticStudio 16.5 Sp1 or later - We recommend updating Windows 10 to the Anniversary Update or later , also known as version 1607 or build 14393. This is because OpticStudio 16.5 Sp3 uses Microsoft .NET 4.6.2, which is bundled with the Anniversary update. This link tells how to verify if you have the Anniversary Update or newer installed. See the ."Error: OpticStudio requires the .NET Framework" section of this article for details on installing the required .NET update separately. 

Once your system has all the required updates above, try and open OpticStudio again.

If it still fails to launch, reinstall and verify the OpticStudio prerequisites file as detailed in the following section - Reinstalling the OpticStudio Prerequisites Package and verifying it.

Error: OpticStudio has stopped working

If you encounter an error message when launching OpticStudio that contains "stopped working" or a similar error, this is usually due to missing or corrupt Windows components required to run OpticStudio. 

TIP: This section only applies if OpticStudio stops working BEFORE opening any files or windows within the application.

Reinstalling the OpticStudio Prerequisites Package and verifying it.

You may need to reinstall the prerequisite bundle. Note that OpticStudio 14 SP2 and later releases have the pre-requisite package bundled in with the installer, so you don't need to install it separately. The preferred method is to launch the OpticStudio_Prerequisites.exe file that is located in your OpticStudio installation folder. The default install folder is C:\Program Files\Zemax OpticStudio.  

After clicking on this executable, you will see a splash screen for the pre-requisites.

Pre-requisites Splash Screen
Prerequisite Installer

The prerequisite installer will perform a combination of registry checks and may reinstall some components, though it will skip any that it finds already exist on the machine.  When complete, it will close automatically. 

Re-launch OpticStudio. If it does not succeed, then move to the following section: 

Verifying the Prerequisite Installation

Once the installation has completed, try to launch OpticStudio again. If it doesn't work, you can verify that all the components have been installed. If you find that any of these components is missing, it is recommended that you try repairing from the Control Panel, or installing the missing component directly from the links provided below. 

Essential OpticStudio components in Apps or Programs and Features

Check for all the following to be installed, and either use the links to reinstall, or repair them. To get to the list of installed applications and updates in Windows follow these steps:

WIndows 7: Open Start > Control Panel > Programs and Features
Windows 8.1: Right-click on the Start icon in the lower left-hand corner to open the Start Context Menu. Select Programs and Features.
Windows 10: Right click on the Start icon in the lower left-hand corner to open the Start Context Menu. Select Apps and Features.

Check all the following are all installed as applicable:

Safenet Sentinel Key Driver NOTE: Not applicable to Green / Red USB licenses. This is only required for Black USB licenses directly connected to the computer. Also available in the "Resource files" section of the OpticStudio Download page.
Microsoft SQL Server Compact 3.5 SP2 x86 (for both 32-bit and 64-bit OpticStudio)
Microsoft SQL Server Compact 3.5 SP2 x64 (for 64-bit OpticStudio only) 

Visual C redistributable installation and repair

One of the most common errors is with the Microsoft Visual C++ Redistributable packages not properly installing, even though they show up in the list of installed programs. Here is a list of required versions with download links if you need to  reinstall them.

WIndows 7 or 8/8.1 example of repairing a Visual C runtime
Change Visual C++ Redistributables Installation

WIndows 10 example of repairing a Visual C runtime

When the Modify Setup dialogue box appears, select Repair.
 Repair Installation

Components not listed in Apps or Programs and features
These components are installed over the internet when installing OpticStudio so will not be installed if offline or blocked on your network. Therefore we recommend reinstalling these as they aren't placed on the list, and because re usually downloaded.

Microsoft .NET Framework

See the "Error: OpticStudio requires the .NET Framework" section of this page for .NET system requirements and download links. Note that if you have a newer release of .NET than required already installed, they are backwards compatible.

Directx runtime

All OpticStudio releases: DirectX 9.0c End-User Runtime Standalone Installer (this version works for offline installations)

When you open the downloaded Directx_Jun2010_redist.exe file, it will ask for a location to extract them to. Type in C:\dx9 for the location, then open dxsetup.exe in that folder.

If everything looks good after repairing or installing the required versions try and launch OpticStudio again.

If you still get a crash upon startup, move to the next section to check for interfering applications.


Check for programs known to interfere with OpticStudio.

Sometimes, 3rd party programs can interfere with the prerequisites for OpticStudio and prevent the program from running. 

Note: Many of these programs have patches or updated releases that correct the behavior. If you have any of these programs installed on your machine, either update to the latest version of the program or remove the program and retry running OpticStudio. You should find that once the program is removed, ZOS is able to execute properly.

The current list of known offenders is:

NVIDIA Geforce Experience 1.6
Adobe Acrobat 9 Pro Extended 64-bit Add-On  (just the add-on, you do not need to remove the whole program)
Adobe Acrobat 9 Pro Extended 32-bit (the whole program appears to be corrupt)
Searchqu Toolbar
TrustBroker Secure Client
PolicyPak (Client Side Extensions)
Total Defense
Replay Media Catcher
Cylance Antivirus

If none of these programs is installed but you receive the Windows errors described above, please try restarting your computer in Safe Mode and running OpticStudio. If it launches in safe mode, it means the interfering program is not running when in safe mode. If ZOS does not launch in safe mode, it means the interfering program is running.

If you are still unable to launch OpticStudio, skip to the Getting Help section.

Issue: OpticStudio hangs at splash screen on startup

This applies if you see the below picture, and it never moves past it. Normally once OpticStudio has located a license, you will see Standard, Professional, or Premium appear at the bottom right.

This issue has been know to happen due to antivirus software blocking some of the files OpticStudio needs to run. 

If your organization uses Mcafee Enterprise, the "Host Intrusion Prevention System" feature may be the cause. To verify if this is the case, as well as work around the issue, you can temporarily turn off HIPS. Note that HIPS is re-enabled upon restart of the computer, so this is not a permanent fix.

1. Right-click the Mcafee icon in the system tray (normally a red shield with an M in the center)
2. Navigate to the Disable Menu, then select Disable HIPS protection.


If this lets you launch OpticStudio, your IT department can set Mcafee to whitelist (mark as safe) the hasp_rt.exe process. This file is located in c:\program files\Zemax OpticStudio.

If this does not fix the issue, check your antivirus software to see if it has blocked any files at the time you launched OpticStudio, particularly anything with HASP in the name or in the Opticstudio installation folder. Also, we recommend you Check for programs known to interfere with OpticStudio. Otherwise, skip to the Getting Help section.

Getting Help

If your installation issue is not resolved, please email and send us:
  • Screen shots or description of any error messages or the behavior you encounter.
  • A summary of any troubleshooting steps you have already taken 
  • If using a USB key, let us know if the key lights up.
  • Your license key number (softkeys are in the format L000000, USB keys are 5 digit numbers)
This will provide us with all the information we'll need to quickly diagnose the problem, or escalate as needed.