Symptoms
After a successful application deployment to SSAS 2025, users encounter errors when loading forms:
- Input forms: "The server sent an unrecognizable response."
- Read-only forms: "Internal error: An unexpected exception occurred."
The application deployment itself completes without errors. Forms fail only when users attempt to load them.
Affected environments
This issue affects applications deployed to SSAS 2025 Enterprise Edition or SSAS 2025 Developer Edition that use SSAS proactive caching (the default setting).
SSAS 2025 Standard Edition, SSAS 2022 and earlier, and applications already using Kepion proactive caching are not affected.
Cause
SQL Server Analysis Services 2025 introduced a breaking change to its SQL client library (see What's new in SQL Server Analysis Services | Microsoft Learn). As a result, SSAS native proactive caching may not function correctly on this version, which can cause errors when forms query data. Kepion proactive caching uses its own change-detection mechanism and is unaffected. See the Workaround section below.
Workaround
Switch the application from SSAS proactive caching to Kepion proactive caching. For more information about proactive caching in Kepion, see application configurations.
Steps:
- Log in to the Kepion application as a system administrator.
- Navigate to the System module.
- Select the affected application.
- Click the Advanced tab.
- In the Proactive Caching dropdown, change the value from "Use SSAS proactive caching when available" to "Use Kepion proactive caching".
- Click Save.
- Redeploy the application.
Repeat these steps for each affected application in the environment.