Troubleshooting your OpticStudio installation

This article explains what to do if you have problems launching OpticStudio, and will help you get your OpticStudio installation running smoothly.

Authored By Alison Yates


This article is organized by error message or issue that may arise in an OpticStudio installation. Please navigate to the section relevant to the issue you are experiencing to find steps to resolve the issue. If the issue persists, the Getting Help section covers support contact.

OpticStudio requests a license code

The first time you run OpticStudio, you may be prompted for a license code as shown below.

If you see this dialog box, your copy of OpticStudio is correctly installed, and the USB key is working properly. You just need a license code to allow this version of OpticStudio to run with your key. To request a license code, refer to How to request an Opticstudio license code.

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. In order to correct this, you will need to check your Windows version and Windows updates. To do this:

  1. Ensure that your Windows version is supported, as per the system requirements on the downloads page. Note that Windows XP and Vista are not supported for any OpticStudio version.
  2. Check for Windows Updates on your PC.
  3. 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.

If you do not want to install all Windows updates, you can manually install the minimum updates OpticStudio requires from the list below.

Windows version Update instructions

Windows 7

Windows 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 above updates are installed, install the Universal C Runtime Update.
  4. Once your system has all the required updates above, try and open OpticStudio again. If it still fails to launch, Move to Reinstalling the Visual C redistributable.

Windows 8

Windows 8.1

Windows Server 2012 R2

Note: Windows 8.0 is not supported by OpticStudio 16.5 Sp1 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

Once your system has all the required updates above, try and open OpticStudio again. If it still fails to launch, Move to Reinstalling the Visual C redistributable.

Windows 10 Windows 10 already contains all required updates, though the Anniversary Update or later (also known as version 1607 or build 14393) is recommended. This link tells how to verify if you have the Anniversary Update installed. Move to Reinstalling the Visual C redistributables


Next, move to the Reinstalling the visual C redistributables section below to verify or reinstall these runtimes.  


Reinstalling the Visual C redistributables

This is usually easily resolved by going into Control Panel...Programs and Features (Windows 7) or Settings....Apps (Windows 10). <Right-click> on each of the redistributable packages, select Change then Repair

If you don't see the appropriate Redistributable versions, they can be downloaded from this link

For Opticstudio 17.5 and higher, check and repair the 2010, 2012 and 2022 Redistributable. 


Modify Setup dialogue box

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

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, see "Identify your OpticStudio license." Use the below table to identify reference resources for Single User licenses, hosted on your machine.

Single User license type Resource

Black USB License


Troubleshooting license issues with a Black USB license

Single User Softkey License


How to troubleshoot Softkey license issues

Red USB License & Green USB License


How to troubleshoot red or green USB license issues


Network licenses:

If you are trying to reach a network server that uses a Black USB network key, refer to the "Client troubleshooting" section of "Installing OpticStudio with a Black USB network hardkey (server and client)."

If you are trying to reach a network server that uses a network softkey license or Red USB network license, refer to "How to install the network license version of OpticStudio." or "Resolving network license issues on client machines".

OpticStudio requires the .NET Framework

OpticStudio requires that the Windows .NET Framework be properly installed. Normally, OpticStudio automatically downloads the required version of the .NET Framework from Microsoft during installation, but errors can occur during the installation. If the .NET Framework has not been proply installed or needs to be repaired, you will receive the following error.   


As of OpticStudio 16.5 SP1, a minimum of .NET 4.6.2 is required. As of Opticstudio 20.3, .NET 4.8 is required.

To correct this error, you need to install the version of .NET (or higher) referred to in the error. Typically this means that Opticstudio was unable to automatically update .NET during the install process. Offline installation files for .NET 4.6.2 is here. NET 4.8 is here.

If you are unable to install .NET, or still unable to launch OpticStudio, skip to the "Getting help" section.

OpticStudio has stopped working or immediately launches the Zemax File Collector

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. In 18.7 and higher, a crash will automatically open the Zemax File Collector utility to allow you to report the crash to us for assistance. Before submitting a crash report, there are some steps to take. 

stopped working

The first step in resolving the above error is to reinstall and verify the OpticStudio Prerequisites Package. To do this:

  1. Launch the OpticStudio_Prerequisites.exe file that is located in your OpticStudio installation folder. The default install folder is C:\Program Files\Zemax OpticStudio. 
  2. After clicking on this executable, you will see a progress box as it installs. The prerequisite installer will perform a reinstall of most components. It will skip any that it finds already exist on the machine and close automatically when done.


  1. Once the installation has completed, try to launch OpticStudio again.
  2. If OpticStudio does not launch properly, you can verify that all the most important components have been installed. 

    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. To fix this, follow the instructions outlined in the above "Reinstalling the Visual C redistributable" section.

  3. Try and Launch OpticStudio again. If you still have troubles, move to the "Getting help" section. 

OpticStudio hangs at splash screen on startup

This section applies if, after launching OpticStudio, the application hangs at the below picture and it never moves past it. Normally once OpticStudio has located a license, you will see your OpticStudio edition (Standard, Professional, or Premium) appear at the bottom right. This is a good indicator that OpticStudio is launching properly. 


If you do not see the edition appear on the splash screen, something is likely blocking OpticStudio from launching properly. This issue has been known to happen due to antivirus software blocking the licensing process OpticStudio needs to run. 

If you have something other than Mcafee Enterprise antivirus/security software, check to see if it has blocked any files at the time you launched OpticStudio. The most common files are anything with "HASP" in the name (e.g. "hasp_RT.exe or hasplms.exe") or files in the OpticStudio installation folder (by default: C:\Program Files\Zemax OpticStudio). If you are unable to find any blocks in the antivirus move to the "Getting help" section. 

If your organization uses Mcafee Enterprise, the "Host Intrusion Prevention System" feature may be the cause. To verify if this is the case and 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. To perform this action:

  1. <Right-click> the Mcafee icon in the system tray (normally a red shield with an M in the center)
  2. Under Disable, select Disable HIPS Protection.

Disable HIPS protection

  1. Try and launch OpticStudio.
  2. If it launches properly, ask your IT department to whitelist (mark as safe) the "C:\Program Files\Zemax OpticStudio\hasp_rt.exe" process in Mcafee's administrator console. 

If this does not fix the issue, proceed to the "Getting help" section.

Getting help

If your installation issue is not resolved, please email If you have OpticStudio 18.7 or higher, you will have the Zemax File Collector come up if OpticStudio crashes. This tool gathers most of the relevant information needed to help with your issue. For help using it, see How to report a problem or possible bug to Zemax Support

Otherwise, please send us the following:

  • 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 and stays lit.
  • Your license key number (red and green USB licenses and softkeys are in the format L100000. Black USB licenses have a 5-digit number like 22000 engraved on them.)

This will provide us with all the information we'll need to quickly diagnose the problem or escalate as needed.

References / other resources

If you experience slow response in graphics windows while running OpticStudio, see "Troubleshooting UI issues in OpticStudio."

If you experience black (or blank) windows within OpticStudio, see "What to do if the graphics windows in OpticStudio are black or blank."


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