After upgrading the Enterprise Layer Manager (ELM) to version 2503, users continue to receive older versions of elastic layers on their virtual desktops, even after the elastic layer assignments have been updated to newer versions.

Additional symptoms observed:

New versions of App Layers are created and assigned elastically, but users still receive the previous version.

• Removing elastic layer assignments does not prevent the layer from attaching; users still see the old version during login.
• The issue started after upgrading ELM from version 2403 or 2409 to 2503.
• No relevant errors are found in the ulayersvc.log.

The root cause is due to the OS layer registry still referencing the old repository path from the previous ELM appliance. After upgrading to ELM 2503, layers are stored in a new repository linked to the new appliance, and assignments are also saved in that location.

To resolve the issue, follow one of the solutions below:

Method 1 – Update the repository path in the registry of the master image:

1. Log into the master image.
2. Open Registry Editor.
3. Navigate to:
   • HKEY_LOCAL_MACHINE\SOFTWARE\Unidesk\ULayer
4. Locate the RepositoryPath registry value.
5. Update it to point to the new repository path used by the ELM 2503 appliance.
6. Update the Machine Catalog in Citrix Studio.

Method 2 – Create a new version of the OS Layer:

1. Create a new version of the OS layer.
2. Update the correct RepositoryPath in the registry.
3. Publish the image and confirm the updated path reflects correctly.
4. Use the image as master image and update the machine catalog.

Method 3 – Use Group Policy Preferences (GPP):

• Configure a Group Policy Preference to push the correct RepositoryPath value to all affected machines (VDAs).

Problem Cause

Problem Cause:

Upgrading to ELM 2503 requires building a new appliance and migrating layers into a new repository. The App Layering system stores assignment files and layer versions in the new repository. However, OS layers that were migrated from the older ELM retain the old repository path in their registry. As a result, during logon, the system reads outdated assignment files and continues to mount the previous versions of elastic layers.

This problem does not generate errors in ulayersvc.log because the process completes successfully using the old repository. If the old path had been disabled, the mounting would have failed—making the issue more visible.