How to fix Error 3749 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 3749 – Cannot Drop XML Index Using Old ‘Table.Index’ Syntax

Why This Error Happens

This error occurs because SQL Server 2025 has deprecated the legacy DROP INDEX table.index_name syntax specifically for XML indexes, requiring the newer ANSI-standard DROP INDEX index_name ON table_name format instead. The old syntax parser cannot correctly resolve the index-to-table relationship for XML index types, triggering a parsing failure. This is purely a T-SQL syntax compatibility issue and is not related to permissions, corruption, or connectivity.

Step-by-Step Resolution Guide

Step 1: Identify the Offending Script or Query

  • Locate the T-SQL script, stored procedure, or application code generating the DROP INDEX statement.
  • Search for patterns matching DROP INDEX [TableName].[IndexName].
  • Use SQL Server Management Studio (SSMS) 21 or Azure Data Studio to open the script for editing.

Step 2: Rewrite the Statement Using ANSI Syntax

  • Replace the old syntax with the supported format: DROP INDEX IndexName ON TableName;
  • Example fix: Change DROP INDEX Employees.IX_XML_Resume to DROP INDEX IX_XML_Resume ON Employees;
  • If dropping a primary XML index, ensure no secondary XML indexes (PATH, VALUE, PROPERTY) depend on it, as they must be dropped first in the same corrected syntax.

Step 3: Update Dependent Automation and Deployment Scripts

  • Check SQL Server Agent Jobs, SSIS packages, and DevOps/CI pipeline scripts (e.g., files in C:\Program Files\Microsoft SQL Server\160\DTS\Packages\) for the deprecated syntax.
  • Update any database migration tools (like DACPAC or Liquibase changesets) to use the new syntax to prevent future deployment failures.

Step 4: Execute and Validate in a Test Environment

  • Run the corrected script against a non-production instance of SQL Server 2025 first.
  • Confirm the command executes without returning Error 3749 or any syntax warnings.

Alternative or Verification Steps

  • Verification: Run SELECT * FROM sys.indexes WHERE name = 'YourIndexName' after execution to confirm the index no longer exists in the schema.
  • Alternative: If modifying legacy application code is not immediately feasible, wrap the drop logic in a sp_executesql dynamic SQL block using the new syntax to bridge compatibility without altering the core application structure immediately.