Why This Error Happens
Error 2399 is typically thrown by SQL Server Analysis Services (SSAS) when the XML metadata engine encounters an attribute in a Data Definition Language (DDL) script or ASSL (Analysis Services Scripting Language) file that does not match the expected data type defined in the schema. This usually occurs due to a corrupted or manually edited .xmla deployment script, a mismatched Compatibility Level between the Analysis Services instance and the project file, or a failed/interrupted metadata migration during an upgrade to SQL Server 2025. In most cases, the root cause is a type mismatch (e.g., a string value passed where an integer or GUID was expected) within the cube, dimension, or data source definition.
Step-by-Step Resolution Guide
Step 1: Validate the XMLA/ASSL Script Integrity
- Open the deployment script (
.xmlaor.asdatabasefile) in SQL Server Management Studio (SSMS) or a text editor. - Search for the specific attribute named in the error message (e.g.,
<ID>,<Type>, or<DataType>) and confirm the value matches the expected schema type (string, integer, boolean, or GUID). - Correct any manually inserted values that do not conform to the ASSL schema definitions found in
C:\Program Files\Microsoft SQL Server\160\Tools\Binn\VSShell\Common7\IDE\...\Microsoft.AnalysisServices.xsd.
Step 2: Check Compatibility Level Alignment
- Right-click the SSAS database in SSMS, select Properties, and verify the CompatibilityLevel matches your SQL Server 2025 instance (should be 1710 or higher).
- If deploying from Visual Studio/SSDT, open the project properties and ensure the Deployment Server Edition and Compatibility Level match the target server.
- Redeploy the project after aligning these values to avoid legacy attribute types being pushed into a newer engine.
Step 3: Rebuild the Corrupted Object Definition
- Navigate to the specific dimension, measure group, or data source referenced in the error stack trace.
- In SSDT, right-click the affected object and select Delete, then recreate it manually using the GUI wizard rather than copy-pasting XML.
- Run
Process Fullon the object via SSMS:
<Process xmlns="http://schemas.microsoft.com/analysisservices/2020/engine">
<Object>
<DatabaseID>YourDatabaseID</DatabaseID>
</Object>
<Type>ProcessFull</Type>
</Process>
- Confirm the Windows Event Viewer (
Applications and Services Logs > SQL Server Analysis Services) no longer logs Event ID 2399 after processing.
Step 4: Restart the Analysis Services Instance
- Open Services.msc on Windows Server 2025, locate SQL Server Analysis Services (MSSQLSERVER), and restart the service to clear any cached metadata locks.
- Re-attempt the deployment or query that originally triggered the error.
Alternative or Verification Steps
- Verify the fix by running
SELECT * FROM $SYSTEM.DISCOVER_XML_METADATAin an MDX query window to confirm the object schema now validates without throwing type exceptions. - If the error persists, restore the SSAS database from a last-known-good backup (
.abffile) taken prior to the SQL Server 2025 upgrade, then re-apply only the verified schema changes incrementally.