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How to Report a Problem or Possible Bug to Zemax Support

This article describes how to report problems or bugs and generate the files the Zemax support team will need to quickly resolve your issue.


Before reporting a problem

OpticStudio Stops Responding Or Shuts Down With An Error

Gathering More Information

Addendum How to create a screen shot
Zemax Support
Installation and Troubleshooting
Frequently Asked Questions
First Time Users

Before Reporting A Problem

First, as with many computer problems, try restarting your computer. That allows updates to complete, and clears apps from memory.

Next, review the Knowledge Base to see if there is an article about your issue. Some common issues are linked in the related articles at the top of this article. Check the Zemax Forums. Other users may have dealt with your issue and found a solution. 

If you are unable to start OpticStudio or cannot locate a license key, please see this KB article which takes you through the troubleshooting steps.

OpticStudio Stops Responding Or Shuts Down With An Error

If you get a crash while using OpticStudio, there are several pieces of diagnostic information that we'd like to help us troubleshoot. You have two options for collecting this information. The easiest way is to (A) Run a tool to automatically collect diagnostic files about your computer. Or option (B) Manually collect diagnostic files

(A) Run a tool to automatically collect diagnostic files:

We have created a diagnostics application to gather important system information and make it easy to report problems. A version has been included in OpticStudio 17 to 18.4 under Help / Feature Experiments. The release on this page is also in OpticStudio 18.7 on the Help / Utilities. If you have an older OpticStudio release, we are providing it here as a convenience. 

Here is a list of the data it collects.

  • All windows event from the ‘Application’ log group that contain the words Zemax or OpticStudio
  • A list of all applications installed on the computer
  • A list of all processes running when the tool was run
  • All output from the Zemax System Diagnostic tool
    • OpticStudio install location and some version information
    • Graphics adapter information
    • Some Zemax registry information
    • Monitor information
    • List of libraries loaded into the System Diagnostic process
    • Render speed test output
  • All KEY_STAT_*.log files and the VERSION.LOG file
  • Miscellaneous other system information:
    • Operating system name and version
    • Is 64-bit?
    • CPU name, clock speed, processor count
    • Physical and available RAM
    • .NET version
    • Temp folder path
  • List of all files in the OpticStudio install folder

1. Download the tool here:

2. Extract all files in this ZIP file to a folder of your choice either by right-clicking the ZIP and selecting "Extract all", or by opening the file and selecting "Extract All" from the Windows menu. An example For WIndows 7 and 10 is below.

Windows 10

Windows 7 extract dialog

3. Open ZemaxFileCollector.exe from the folder you extracted the files to. You will be presented with the following screen. Please type in a description of *exactly* what you were doing when the crash occurred. You can also add steps to reproduce and any additional comments. Click Next. 

4. It will automatically start gathering information, and display it when done. Review the list. if you need to remove any from the diagnostics package they can be unchecked now. All files are text-based so you can see exactly what is included.

5. Click "Add additional files" if you have any screen shots, logs, or other files you would like to include. We recommend additional files total ~20MB or smaller. That should allow you to keep under most email size restrictions. If the issue happens when working with a particular optical system, you can include a ZAR archive which will help reproduce the problem.

TIP: To create a ZAR file, Go to File / Create Archive in OpticStudio. 

6. Click Save Diagnostics Package. It will save a file called DiagnosticsPackage-******.ZIP file into the same folder as the File Collector application. It will also copy the file into the Windows Clipboard so it can be pasted into an email.


7. Click "Email technical support". It will try and open a new message in your Windows default email client. Right-click and select Paste or use Ctrl-V to attach the DiagnosticsPackage-******.ZIP file. Then send it to the Zemax support team. 

TIP: if the Email button doesn't open a new message, or the wrong email client, you can also email from your normal email client or web site. Be sure to hit Ctrl-V or attach the DiagnosticsPackage-******.ZIP file to the email. 


(B) Manually collect diagnostic files: 

Please follow steps 1-6, and send all the collected information to

1. The first is a simplified ZAR sample file with which you observe the crash (if applicable). Often it is a specific combination of components that cause the crash, and the sample file will give us a much better chance of reproducing the crash. If we can reproduce it, we can fix it. To create a ZAR file, Go to File / Create Archive in OpticStudio. 

2. A description of *exactly* what you were doing when the crash occurred.

3. The event logs (.EVTX files) from the Windows Event Viewer described in the Gathering More Information section.

4. The System Diagnostics log file "ZemaxGraphicsInfo.txt" from the Gathering More Information section.

5. The version and release date of OpticStudio you are using, and your license key number. That can be found in Help / About in OpticStudio. 

6.  KEY_STAT FILES. - Please send any KEY_STAT_X.LOG files from your <C:\Users\(username)\Documents\Zemax\License> folder.

Potential Bugs

Like any software, occasionally, we find bugs in the OpticStudio calculations. Some bugs are apparent, such as a command for one thing returning something else entirely, but others are more nuanced. If you think you've spotted a bug in OpticStudio, let us know! 

Note that in many cases, bugs in old releases have already been fixed in new releases, so making sure you're up to date with the latest OpticStudio version is always a good thing to try. It's also recommended to be sure that Windows itself is up to date with all service packs and security patches. 

If you would like us to look into a possible bug, please send an email to with the following:

1. A simpilfied ZAR sample file that demonstrates the problem. To create a ZAR file, Go to File / Create Archive in OpticStudio. 

2. A description of *exactly* what you were doing when the bug occurred, or what results are in question.

3. A screenshot of the System Diagnostics windows and log file "ZemaxGraphicsInfo.txt" from the Gathering More Information section of this document.

4. The version and release date of OpticStudio you are using, and your license key number. That can be found in Help / About in OpticStudio.

Gathering More Information

Event Logs

Whenever an application crashes or hangs, an event is logged in the Windows Event Viewer. These event logs are often very helpful to us as we try to diagnose the problem. To save an event log, follow these steps.

1. Type “Event” in the Windows search bar to pull up the Event Viewer: 

Finding the event viewer

2. Click on “Error” and select “View All Instances of This Event”:

Save Events

3. You can then use the time stamps to find the appropriate event when the application crashed. Note that often, it’s either OPTICSTUDIO.EXE or the .NET Runtime error that is applicable. However if there are multiple errors that are around the same time you had the issue, get all of them. It's better to have too many than not enough! You may select multiple items by holding the CTRL key on your keyboard while clicking on each event. Once you have selected all the ones you want, let go of CTRL.

4. Click “Save selected Events” to generate the *.EVTX file. 

View All Errors


System Diagnostics 

OpticStudio includes a built-in System Diagnostics utility, which will gather useful information about your system, graphics card, and settings. To get this information, follow these steps.
  1. Click Help / System Diagnostics in OpticStudio.

2. Click "Save Output". It will save a file called “ZemaxGraphicsInfo.txt.”  Please save this file, as well as a screenshot of the results as below. 


Sentinel Advanced Medic and Key_stat files (Inventory of Installed Software and Black USB key information)

This utility is useful to give an inventory of software installed, and help diagnose issues with a black USB dongle. This will not diagnose red or green USB keys. 

Instructions to use the Sentinel Advanced Medic: 

1. Download the Sentinel Advanced Medic from this link
2. Run the sentinel_medic_1.3.exe file you downloaded. It will by default extract to c:\sentinel_medic_1.3 (though you can change the folder).
3. After extraction completes, it will launch the Sentinel Medic application automatically. 
4. Check the "Enable logging" box. 
5. Start the diagnostic test by clicking the "Troubleshoot" button.
6. You may have to press the "Acknowledge" button a few times until it changes to "Done".

7. Once it is done, please take a screenshot of the diagnostics test results window (the screenshot above is what we are looking for).
Also, save the log file called Sentinellog.txt located in the folder the sentinel medic extracted to. The default is c:\sentinel_medic_1.3.

8. Also helpful for USB key issues and application crashes is the KEY_STAT_*.LOG files from your Documents\Zemax\License folder.


Addendum: How to Create A Screen Shot

If you don’t have an application on your computer to capturing a portion of your computer screen, you can use the Snipping Tool that is built into Windows. You can find the tool by searching “snip” in any version of Windows 7 or higher: