How to fix Error 2787 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: Error 2787 – “Invalid format specification: ‘%.*ls'”

Why This Error Happens

Error 2787 in Microsoft SQL Server 2025 typically occurs when an internal formatting routine receives an unexpected or corrupted string token while rendering a dynamic error message, often triggered by corrupted system catalog resources, mismatched localization/resource DLL files, or a damaged errorlog message cache. This can also surface after an incomplete Cumulative Update (CU) installation on Windows Server 2025 / Windows 11, where resource strings in sqlevn70.rll or related language resource files do not align with the SQL Server binary version. In rarer cases, it stems from a corrupted installation of SQL Server Native Client components used to parse extended string formatting during error-raising operations (e.g., RAISERROR with malformed placeholders).

Step-by-Step Resolution Guide

Step 1: Verify SQL Server Build and Resource File Consistency

  • Open SQL Server Management Studio (SSMS) and run SELECT @@VERSION; to confirm the exact build number.
  • Navigate to C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Binn\Resources\1033\ and check that sqlevn70.rll matches the installed SQL Server build version.
  • If mismatched, this confirms a broken or partial patch installation.

Step 2: Reapply the Latest Cumulative Update

  • Download the latest SQL Server 2025 Cumulative Update from the official Microsoft Download Center.
  • Run the installer as Administrator: Setup.exe /Action=Patch /IAcceptSQLServerLicenseTerms /Quiet.
  • Allow the patch to fully repair binary and resource files, then restart the SQL Server service via services.msc or net stop MSSQLSERVER && net start MSSQLSERVER.

Step 3: Check for Corrupted or Malformed RAISERROR Statements

  • Review any custom stored procedures, triggers, or jobs using RAISERROR with format specifiers (e.g., %s, %ls, %.*ls).
  • Search user databases using:
  SELECT name, definition 
  FROM sys.sql_modules 
  WHERE definition LIKE '%RAISERROR%';
  • Correct any malformed format strings missing matching arguments.

Step 4: Run a SQL Server Repair Installation

  • Open Control Panel > Programs > Programs and Features, select Microsoft SQL Server 2025, and click Change.
  • Choose Repair from the SQL Server Installation Center wizard.
  • Reboot Windows Server 2025 / Windows 11 after the repair completes.

Step 5: Validate System Resource Integrity

  • Run sfc /scannow from an elevated Command Prompt to rule out underlying OS-level file corruption affecting shared language resources.
  • Restart the SQL Server and SQL Server Agent services afterward.

Alternative or Verification Steps

  • Re-run the operation or query that originally triggered Error 2787 and confirm the error no longer appears in the SQL Server Error Log (Management > SQL Server Logs in SSMS).
  • If the issue persists, uninstall and cleanly reinstall SQL Server 2025 using a fresh ISO, ensuring no leftover resource files remain in the Binn\Resources directory beforehand.