How to fix Error 10314 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 10314 – CLR Assembly Load Failure

Why This Error Happens

Error 10314 occurs when the SQL Server CLR (Common Language Runtime) integration fails to load a managed assembly, typically because the server has exhausted available memory or virtual address space needed by the .NET Framework host. This can also result from a corrupted assembly in the database, conflicting CLR versions, or the clr enabled configuration interacting poorly with memory pressure from other SQL Server subsystems. In some cases, Windows Server 2025 security policies (like AppLocker or Code Integrity) may block the assembly load, which SQL Server misreports as a resource issue.

Step-by-Step Resolution Guide

Step 1: Verify CLR Integration Status and Memory Pressure

  • Run sp_configure 'clr enabled' to confirm CLR is active on the instance.
  • Check sys.dm_os_memory_clerks for the MEMORYCLERK_SQLCLR entry to see current memory consumption.
  • Review Windows Performance Monitor counters (SQL Server:Memory Manager > Target Server Memory vs Total Server Memory) for signs of memory exhaustion.

Step 2: Increase Server Resources or Adjust Memory Configuration

  • Open SQL Server Management Studio (SSMS) and navigate to Server Properties > Memory.
  • Increase the “Maximum server memory” value if it’s set too restrictively, leaving at least 4–6 GB for the OS on Windows Server 2025.
  • If running in a virtualized environment, confirm the VM has not hit a memory ballooning or Hyper-V dynamic memory limit.
  • Restart the SQL Server service after adjustments via services.msc or net stop MSSQLSERVER && net start MSSQLSERVER.

Step 3: Rebuild or Re-register the Faulty Assembly

  • Identify the problematic assembly using the id referenced in the error: 
  SELECT name, assembly_id FROM sys.assemblies WHERE assembly_id = <id>;
  • Drop and re-add the assembly if corruption is suspected:
  DROP ASSEMBLY [YourAssemblyName];
  CREATE ASSEMBLY [YourAssemblyName] FROM 'C:\Path\To\YourAssembly.dll' WITH PERMISSION_SET = SAFE;
  • Ensure the assembly file itself isn’t blocked by Windows (right-click DLL > Properties > Unblock).

Step 4: Check Windows Security and Code Integrity Policies

  • Review Windows Defender Application Control (WDAC) or AppLocker logs in Event Viewer under Applications and Services Logs > Microsoft > Windows > CodeIntegrity.
  • Temporarily disable Code Integrity enforcement in a test environment to confirm if it’s blocking the assembly load.
  • Add an explicit allow rule for the SQL Server CLR assembly path if policies are confirmed to be the cause.

Alternative or Verification Steps

  • After applying fixes, run a test query that invokes the CLR function/assembly directly and confirm no Error 10314 appears in the SQL Server logs (EXEC xp_readerrorlog).
  • If the issue persists, consider migrating the CLR assembly logic to a native T-SQL or external service (e.g., Azure Function) to eliminate reliance on in-process CLR hosting entirely.