Activate or transfer a Zemax softkey license without internet access (Zemax legacy)

This article describes how to activate a new license or transfer a Zemax legacy softkey license when working on an isolated computer without internet access. In order to activate licenses on such computers, a manual process must be followed. The steps are the same for all Zemax products. 

If you are using Ansys-licensed versions of Zemax software, see Ansys Zemax licensing overview and guides.

Authored By Don Dickinson


This article describes how to activate or transfer a Zemax legacy softkey license when working on an isolated computer without internet access.

Before proceeding, please read:

This article applies to software licensed via legacy Zemax softkey licenses. This does not apply to any USB license as they come already activated.

Legacy Zemax softkey licenses include 6-digit alpha-numeric serial numbers beginning with "L" or "T" (e.g. L100000).  You can identify your license type using the guide located here: How to identify your legacy Zemax license.

If you are using Ansys-licensed versions of Zemax software, see Ansys Zemax licensing overview and guides.


If the machine hosting your softkey license does have internet access, you should refer to one of the following articles to activate, transfer or update a license  or Transferring and updating a softkey license


Activate a softkey license without internet

When you initially purchase an OpticStudio or OpticsViewer softkey license, you will receive an automated email from The email will contain an activation code which requires internet access. If the machine you want to activate does not have internet access, follow the instructions below.

Important Notes before activating

  • These steps require you have installed the Zemax License Manager or the application you have purchased on the machine you are activating (OpticStudio, OpticsViewer, or OpticsBuilder). Ansys versions do not work with Zemax softkey licenses (serial numbers L1XXXXX or T1XXXXX). If you are using Ansys-licensed versions of Zemax software, see Ansys Zemax licensing overview and guides.

  • Licenses can only be activated once. If you have previously activated a different machine with this license, refer to the license transfer section of this article instead.

  • If you are trying to reactivate a licensed machine that was lost, stolen, has the operating system reinstalled, do not follow this process. The license is lost and subject to the Zemax Licensing Policy. 

  • Softkey licenses cannot be activated on Apple machines that use Bootcamp (dual boot) for Windows as they are not compatible.

  • Not all license types support offline activation. Once you submit the request we will let you know if this is not the case. 


Request a license file

Once you have the appropriate software (OpticsViewer, Opticstudio, OpticsBuilder or Zemax License Manager) installed, you need to request and apply the license to your machine using the steps below. 

  1. Open the Zemax License Manager located in the Windows Start menu > Zemax Opticstudio (or OpticsViewer) or "Start Menu > Zemax License Manager" folder.

  2. For the Classic Zemax License Manager (versions dated November 2018 or earlier), click Launch Sentinel Admin Control Center at the top.

    For the Zemax License Manager Versions dated May 2019 or later, select Troubleshoot > Launch Sentinel Admin Control Center.

    Alternatively, open a web browser, and go to http://localhost:1947. Note that this is a local page on your machine and does not require an internet connection.

    Tip: If the Admin Control Center page gives an error , then the Sentinel licensing drivers did not install properly. Refer to "Repairing the license runtime" in  "How to troubleshoot softkey license issues. Return to this article once the Sentinel Admin Control Center is working.

  1. In the Sentinel Admin Control Center, navigate to the Diagnostics section, and click Create ID File

  2. An ID file (named "") will be saved on your machine, typically in the Windows "Downloads" folder.

    Tip: Do not change any computer hardware or the Windows computer name / domain before receiving the activation file from Zemax or after activating the license. This will trigger the copy protection or cause the license file to fail to apply.
  3. Attach the ID file to an email addressed to with subject “Softkey Activation: V2C Required”. Please include your license serial number (it starts with L1 such as L100000) in the subject of the email.

  4. We will then reply within one business day with a .v2c activation file. Save that file to your machine  then continue the instructions below.

    Applying the activation file

1. Open the Zemax License Manager, then Sentinel Admin Control Center again. 

2. Click on Update/Attach in the left-hand navigation bar. 

3. Click Choose File and locate the .v2c file you saved.

4. Click Apply File to activate the license and lock it to the machine. 

5. You can now open the Zemax License Manager, and you will see your new softkey's details under License Information.

6. You may delete the .v2c file after installation, as it is one-time use only. 

7. Please review the Zemax Licensing Policies to see how to best protect your softkey license from loss and the policy if it is lost.

If you need to move the activated license to a different machine in the future, follow the license transfer instructions described in "Transferring a Zemax softkey license" (requires internet) or the "Transfer a softkey license from/to a machine without internet" section of this article. 


Transfer a softkey license from/to a machine without internet

This section describes the process for transferring a softkey license from a machine that does not have internet access or to a machine that does not have internet access.

Important notes before beginning

  • You will need to download the Zemax_RUS tool to both the machine currently hosting the license (the source machine) and the machine to which you want to transfer the license (the destination machine). The Zemax_RUS tool will create a destination file and a transfer file to be used during the transfer.
  • The license must be activated and working on the machine you are transferring it away from. If the licensed machine was lost, stolen, has the operating system reinstalled or has crashed, the license is lost and subject to the Zemax Licensing Policy.
  • The Zemax License Manager, Opticstudio or other Zemax legacy products must also be installed on both the source machine and the destination machine before beginning. 
  • You will need a location accessible to both machines to transfer the license files and Zemax_RUS tool. We suggest a USB storage drive or an internal network share.

Once you have the Zemax_Rus tool on both machines and all of the above are true, follow the steps below to complete the transfer. 

TIP: The term source machine refers to the machine where the license is currently activated. The term destination is the machine you are moving the license to. 


Part 1 - Generating an ID file on the destination machine

  1. Start on the destination machine (where you want to move the license to). Verify that the licensing software is working by opening a web browser and navigating to the http://localhost:1947 (Sentinel Admin Control Center). Your machine does not need internet access to load this page – it is an application that runs on your machine via a web browser. It should go to the help page that looks similar the image below. 

    If this page opens to an error message, then the Sentinel LDK licensing runtime required to use your OpticStudio license did not install properly. Refer to "How to troubleshoot softkey license issues" "repairing the license runtime" section. Return to this article and move to Step 2 once the Sentinel Admin Control Center is working.

  1. Open Zemax_RUS and navigate to Transfer License tab.  Save a recipient information (.ID) file to your desktop by clicking the "..." button.

    We suggest you name the file  to match the steps in this article and click Save. However, the particular file name is not important.

3. Click Collect and Save Information. This will display a notice that the recipient information is stored in the file. ​​​​​​​Do not skip this step or the transfer process will fail.

Important: Do not change any computer hardware or the Windows computer name / domain on the machine you created the destination.ID file on until after completing the offline transfer process. Doing so may cause the transferred license to be disabled or the process to fail.


Part 2  - Creating the license transfer file on the source machine 

  1.  Move or login to the source machine

  2. Copy the "" file you created above to the source machine.

  3. Confirm that you are moving the correct license. You need to find the 
    "key id" by opening the Zemax License Manager application. This is located in the Windows Start menu under either the Zemax Opticstudio, Zemax License Manager or OpticsViewer folder.

    For License Manager versions dated Nov 2018 or earlier, navigate to the License Information tab. The Key ID is just below the Key serial number .

    For License Manager versions dated May 2019 or later, open the View License tab. Click the License Number (such as L100000) to bring up the License Details page and find the key id. 


  4. Verify there is NOT an "activated" checkbox next to the license number you want to transfer. If there is, this license cannot be transferred offline. Stop the procedure and contact Zemax support.

  5. Verify the key id you want to use says "Local". if it doesn't say local, you are not logged into the machine where the license is activated.

  6. Verify the license is not in use by closing all instances of Zemax software in the machine.

    If you are moving a network license, you also need to make sure there are no open client sessions using the license. You can check which client machines have an open session by opening the Sentinel Admin Control Center @ http://localhost:1947/_int_/sessions.html as described in this article.

    TIP: The fastest way to close all client sessions is to disconnect the licensed machine from your network as you cannot force clients to disconnect otherwise. Any client machines that lose access to the license will be able to save their file before quitting. 

  7. Open the Zemax_RUS application.

  8. Navigate to Transfer License tab and select the Key ID of the license you want to transfer you found in step 6.

  9. In this example, we are going to transfer license number L101601. So to transfer L101601, select the Key ID 855860311232220694.

  10. Click the "..." button next to "Read the recipient information file from" and select the “” file that you copied from the destination machine. Click Open.

     14. Click the “” button next to "Generate the license transfer file to."

     15. Save the file as “TransferFile.h2h” (we use this name in this example, but the particular file name is not important).

Important Tip: If you are transferring more than one license, be sure to give each license a different transfer file name (including the license number is a good way to do this. For example L123456transfer.h2h).  DO NOT overwrite one transfer file with another. If you do so, you will have lost the license you overwrote. If it is lost, your license will be subject to the Zemax Licensing Policies

     16. Select Generate License Transfer File. You will see a message asking to confirm that you want to transfer your license away to the destination computer name (Owner-PC in the image below). Click Yes to confirm.

Important Note: Your softkey license is now contained in the "transferfile.h2h" file. Make sure not to lose this file. If it is lost, your license will be subject to the Zemax Licensing Policies. We recommend copying rather than moving the transfer file from the source machine to your transfer media in case it is lost or damaged in transit.


Part 3 - Completing the license transfer on the destination machine


     17. Move to the destination machine and copy the generated "TransferFile.h2h" to it.

     18. Open the Zemax_RUS tool.

     19. Navigate to the Apply License File tab. Select "...." button next to Update File. Browse and select the TransferFile.h2h file. Click Open.

     20. Click Apply Update.

     21. You should get a message that the update was successfully applied.

To ensure that the license has been transferred successfully and is working, open the Zemax License Manager. Navigate to the License Information or View License tab and confirm the license is in the list. If you will be running OpticStudio or other Zemax software on the destination, open it and verify it recognizes the license as well.

If you have any troubles with this process, see the "Getting help" section below.

Getting help

If you receive any error messages while activating, transferring or updating, contact Zemax Support for further help. Please include:

  • your license number (such as L000001)
  • any error messages
  • a screen shot of the Sentinel Keys page located in the Sentinel Admin Control Center.


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