How to fix Error 2370 on Windows Server 2025 / Windows 11

by

Troubleshooting Guide: SQL Server Error 2370 – XQuery Expression Parsing Failure

Why This Error Happens

Error 2370 occurs when SQL Server’s XQuery parser encounters unexpected or malformed syntax after what it determined should be the logical end of an XQuery expression, typically due to extra characters, unbalanced brackets, or stray tokens left in the query string. This commonly results from improperly concatenated dynamic XQuery strings, copy-paste errors introducing hidden characters, or mismatched quotes/parentheses within .query(), .value(), .exist(), or .nodes() method calls on XML data types. In some cases, this also stems from application code (such as ORM-generated queries) that incorrectly builds XPath/XQuery strings with trailing or duplicated tokens.

Step-by-Step Resolution Guide

Step 1: Isolate the Offending Query

  • Capture the exact T-SQL statement using SQL Server Profiler, Extended Events, or the Windows Event Viewer (under Applications and Services Logs > MSSQLSERVER) to find the full error text, which includes the problematic token in place of %ls.
  • Run the query manually in SQL Server Management Studio (SSMS) connected to your SQL Server 2025 instance to reproduce the error in isolation.

Step 2: Inspect and Correct the XQuery Syntax

  • Check for unbalanced parentheses, brackets, or quotation marks within the XML method calls, e.g., column.query('/Root/Element[1]').
  • Look specifically for trailing characters after the final closing bracket of the expression, such as stray ), ], or ' characters left over from string concatenation.
  • Validate that any dynamically built XQuery strings (from application code or stored procedures) are not appending extra delimiters or whitespace artifacts.

Step 3: Rebuild Dynamic Query Strings Safely

  • If the XQuery is generated programmatically (e.g., in C#, Python, or via an ORM), refactor the string-building logic to use parameterized construction rather than raw concatenation.
  • Use PRINT or SELECT statements in a T-SQL script to output the final constructed XQuery string before execution, allowing visual inspection for syntax errors.
  • Example check in SSMS:
DECLARE @xquery NVARCHAR(500) = '/Root/Element[1]/Value'
SELECT @xquery

Step 4: Update SQL Server and Validate XML Schema Collections

  • Ensure SQL Server 2025 has the latest Cumulative Update (CU) installed via SQL Server Setup > Check for Updates, since XQuery parser edge-case bugs are periodically patched by Microsoft.
  • If the XML column uses a typed XML Schema Collection, verify the schema definition itself doesn’t contain malformed XPath constraints by reviewing it with:
SELECT xml_schema_namespace('SchemaName', 'SchemaCollectionName')

Step 5: Test in a Clean Query Window

  • Strip the query down to its simplest form (minimal XML fragment and simplest XPath) and incrementally rebuild complexity to pinpoint exactly which clause introduces the extra token.
  • Remove any non-printable or Unicode characters that may have been introduced via copy-paste from documentation or web sources using a plain text editor (e.g., Notepad) before re-running in SSMS.

Alternative or Verification Steps

  • Verify the fix by re-executing the corrected query in SSMS and confirming it returns expected results without Error 2370, then re-test through the original application workflow to confirm end-to-end resolution.
  • As an alternative, if the issue stems from a third-party application or ORM-generated query, check the vendor’s documentation or support forums for known XQuery generation bugs specific to SQL Server 2025 compatibility, and apply any recommended patches or configuration overrides.