How to fix Error 1091 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 1091 – “The option “%ls” is not valid for this function”

Why This Error Happens

This error occurs when a T-SQL statement references a function option, parameter, or property flag that is either misspelled, deprecated, or unsupported by the SQL Server 2025 database engine. It commonly surfaces when scripts written for older configurations (such as legacy DBCC, sp_configure, or metadata functions) pass an argument that the function no longer recognizes due to engine changes in SQL Server 2025. Corrupted or outdated compatibility-level settings on the database can also trigger this mismatch between the expected option set and the one actually being parsed.

Step-by-Step Resolution Guide

Step 1: Identify the Offending Statement

  • Check the SQL Server Error Log at C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Log\ERRORLOG for the exact query or batch that triggered Error 1091.
  • Use SQL Server Profiler or Extended Events (xEvents) to capture the precise statement and the invalid option string.
  • Run SELECT * FROM sys.dm_exec_requests WHERE session_id = <id> to correlate the failing session.

Step 2: Validate Function Syntax Against SQL Server 2025 Documentation

  • Compare the flagged option against the current Microsoft Docs reference for that specific function (e.g., DBCC, OPENROWSET, sp_configure).
  • Look specifically for deprecated keywords — SQL Server 2025 removed or renamed several legacy options compared to SQL Server 2019/2022.
  • Update the script to use the current supported parameter name or equivalent replacement function.

Step 3: Check Database Compatibility Level

  • Open SQL Server Management Studio (SSMS) and run:
  SELECT name, compatibility_level FROM sys.databases;
  • If the compatibility level is outdated (below 160), update it to match SQL Server 2025 standards:
  ALTER DATABASE [YourDBName] SET COMPATIBILITY_LEVEL = 170;
  • Restart the SQL Server service via services.msc or Restart-Service MSSQLSERVER in PowerShell (Run as Administrator) to apply changes cleanly.

Step 4: Rebuild or Refresh Affected Stored Procedures

  • If the error originates from a stored procedure using a deprecated option, drop and recreate it with corrected syntax.
  • Run sp_refreshsqlmodule 'SchemaName.ProcedureName' to ensure cached metadata is updated.
  • Clear the procedure cache if needed: DBCC FREEPROCCACHE;

Alternative or Verification Steps

  • Re-run the original query or job that failed; confirm no Error 1091 appears in the Error Log or SSMS Messages pane.
  • If the issue persists, restore the affected database from a pre-upgrade backup and re-apply only verified, compatible scripts to isolate the exact breaking change.