How to fix Error 1010 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 1010 – “Invalid Escape Character ‘%.*ls'”

Why This Error Happens

This error occurs when SQL Server’s T-SQL parser encounters an invalid or unsupported escape character sequence, typically within a LIKE clause, a string literal, or a query that uses the ESCAPE keyword incorrectly. It is often triggered by malformed queries generated by ORMs, linked server queries, or scripts migrated from other database platforms (like MySQL or PostgreSQL) that use different escape syntax. Corrupted collation settings or incompatible client drivers communicating with SQL Server 2025 can also cause the parser to misinterpret a valid character as an escape sequence.

Step-by-Step Resolution Guide

Step 1: Identify the Offending Query

  • Check the SQL Server Error Log via SSMS or C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Log\ERRORLOG to find the exact statement that triggered the event.
  • Use SQL Server Profiler or Extended Events (xEvents) to capture the specific batch text associated with Error 1010.
  • Look specifically for LIKE clauses containing stray percent (%), underscore (_), or bracket ([) characters.

Step 2: Correct the T-SQL Syntax

  • Ensure that any literal special character in a LIKE clause is explicitly defined using the ESCAPE keyword.
  • Example of a fix: Change WHERE Column LIKE '%50%\%' to WHERE Column LIKE '%50%!%' ESCAPE '!'.
  • Verify that the escape character defined (e.g., ! or \) is a single character and is not null.

Step 3: Validate Client Driver Compatibility

  • Navigate to Control Panel > ODBC Data Sources (64-bit) and verify the driver version connecting to SQL Server 2025.
  • Update the client machine to use the latest Microsoft ODBC Driver 18 for SQL Server or the updated OLE DB Driver, as older drivers may incorrectly encode string literals before sending them to the server.
  • Restart the “SQL Server” service via services.msc after updating connectivity components on the Windows Server 2025 host.

Step 4: Check Database Collation Settings

  • Run SELECT DATABASEPROPERTYEX('YourDB', 'Collation'); to check for collation mismatches between the database and the server instance.
  • If a mismatch exists between a Linked Server (e.g., Azure SQL) and the local SQL Server 2025 instance, align the collations to prevent character set misinterpretation.

Alternative or Verification Steps

  • Verification: Re-run the specific query isolated in Step 1 directly in a new SSMS query window. If the query executes without the “Invalid escape character” error (1010), the syntax correction was successful.
  • Alternative: If the error persists only on a specific application (not in SSMS), bypass the issue temporarily by using CHARINDEX() or PATINDEX() functions instead of LIKE...ESCAPE to search for the string pattern, as these functions handle special characters differently.