How to fix Error 3869 on Windows Server 2025 / Windows 11

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Why This Error Happens

Error 3869 is typically a benign informational message generated during SQL Server startup when the Memory-Optimized Data Filegroup configuration is validated against the resource pool settings. This message appears when SQL Server 2025 checks the Hekaton (In-Memory OLTP) engine state and confirms that the existing checkpoint file pairs (CFPs) and container bindings already match the expected configuration, meaning no schema or storage changes are required. While not a true error, it can repeatedly populate the SQL Server Error Log if verbose logging is enabled, causing confusion during audits or monitoring scans on Windows Server 2025.

Step-by-Step Resolution Guide

Step 1: Confirm the Message Severity in SQL Server Logs

  • Open SQL Server Management Studio (SSMS) and navigate to Management > SQL Server Logs.
  • Filter for Event ID 3869 and confirm the severity level is 10 (informational), not 16 or higher.
  • Run EXEC sp_readerrorlog 0, 1, 'memory-optimized'; to isolate the exact log entries.

Step 2: Validate the Memory-Optimized Filegroup Configuration

  • Execute the following query to check the current state of your memory-optimized filegroups:
  • SELECT name, type_desc FROM sys.filegroups WHERE type = 'FX';
  • Ensure the container path exists on disk (e.g., C:\SQLData\MemoryOptimized\) and that the Windows Server 2025 service account has Full Control permissions on that directory.

Step 3: Suppress Redundant Logging (If Message is Recurring)

  • Open SQL Server Configuration Manager and locate the SQL Server (MSSQLSERVER) service properties.
  • Under the Startup Parameters tab, verify trace flag -T3459 (if present) is not causing excessive Hekaton validation logging.
  • Remove unnecessary trace flags related to In-Memory OLTP diagnostics and restart the SQL Server service via net stop MSSQLSERVER && net start MSSQLSERVER.

Step 4: Rebuild the Resource Pool Bindings (If Configuration Drift is Suspected)

  • Run ALTER RESOURCE POOL [default] WITH (MIN_MEMORY_PERCENT = 0, MAX_MEMORY_PERCENT = 100); followed by ALTER RESOURCE GOVERNOR RECONFIGURE;
  • This forces SQL Server to re-evaluate and rebind the memory-optimized filegroup to the correct resource pool, clearing any stale configuration flags.

Alternative or Verification Steps

  • Verify the fix by restarting the SQL Server instance and checking the Error Log again for Event ID 3869 — it should either not reappear or appear only once at startup without any follow-up errors (e.g., 41342 or 41316).
  • If the message persists excessively, use Windows Event Viewer (Applications and Services Logs > MSSQLSERVER) to cross-reference whether a third-party backup or monitoring agent is repeatedly triggering a filegroup validation check.