How to fix Error 2326 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 2326 (XML Tag Mismatch)

Why This Error Happens

Error 2326 occurs when SQL Server’s XML parser encounters a malformed XML document where closing tags do not correctly correspond to their matching opening tags, often due to manual edits, truncated files, or encoding corruption. This typically happens during operations involving XML data types, SSIS package imports, policy-based management XML configurations, or when loading XML-formatted configuration files (such as Reporting Services RSReportServer.config or Availability Group XML metadata). The root cause is almost always a structurally invalid XML source file rather than a SQL Server engine defect itself.

Step-by-Step Resolution Guide

Step 1: Identify the Exact Source of the Malformed XML

  • Check the full error message for the line number referenced (e.g., “from line %u”) to pinpoint the exact location in the XML document.
  • If the error originates from a specific query, run SELECT * FROM sys.dm_exec_requests to identify the session and query generating the XML parse call.
  • If it’s a config file issue, locate relevant files such as C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Log\ for SQL error logs or C:\Program Files\Microsoft SQL Server\160\Shared\ for shared XML schemas.

Step 2: Validate and Repair the XML Document

  • Open the XML file in a dedicated XML validator (Visual Studio Code with XML extension, or Notepad++ with the XML Tools plugin) rather than a plain text editor.
  • Search specifically for mismatched tags, especially nested namespaces like <ns:element> that may have been incorrectly closed as </element> instead of </ns:element>.
  • Check for truncation at the end of the file — a common cause is an incomplete file transfer or a process that was killed mid-write, leaving the closing root tag missing entirely.
  • Re-save the file using UTF-8 encoding without BOM to avoid introducing hidden invalid characters that confuse the parser.

Step 3: Restore from a Known-Good Backup or Template

  • If the corrupted XML is a system configuration file (e.g., ReportServer.config or an SSIS .dtsx package), restore a previous version from backup rather than attempting manual repair.
  • For SSIS packages, open the .dtsx file in SQL Server Data Tools (SSDT) and use the designer view to re-save it, which forces SQL Server to regenerate valid XML structure automatically.
  • Replace the corrupted file in its original directory path and restart the associated service (e.g., SQL Server Reporting Services via services.msc).

Step 4: Re-run the Operation and Monitor the Log

  • Re-execute the query, import, or service startup that originally triggered Error 2326.
  • Monitor the SQL Server Error Log in real time using EXEC sp_readerrorlog 0, 1, N'2326'; to confirm the error does not recur.

Alternative or Verification Steps

  • Verify the fix by running the XML through an independent validator (such as xmllint --noout yourfile.xml in a WSL/Linux shell on Windows 11) to confirm zero schema errors before reloading it into SQL Server.
  • If the error persists after XML repair, use SELECT CAST(your_column AS XML) in a test query against the specific data to isolate whether the corruption exists at the database row level rather than in an external file, and restore that specific table from a recent backup if confirmed.