How to fix Error 8002 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: TDS RPC Error 8002 (Invalid XML Database or Schema)

Why This Error Happens

This error occurs when a client application sends an RPC call containing an XML-typed parameter that references a database or schema collection that SQL Server 2025 cannot resolve in the current connection context. Typically, this happens because the XML schema collection was defined in a different database than the one the session is currently using, the schema collection name is misspelled or was dropped, or the client-side driver (ODBC/OLE DB/ADO.NET) is sending malformed metadata for the XML parameter. It can also surface after an in-place upgrade to SQL Server 2025 if legacy TDS client libraries are not fully compatible with updated XML type-handling in the RPC stream.

Step-by-Step Resolution Guide

Step 1: Verify the XML Schema Collection Exists and Is Scoped Correctly

  • Run SELECT * FROM sys.xml_schema_collections; in the target database to confirm the schema collection referenced by the parameter actually exists.
  • Confirm you are querying the correct database context — XML schema collections are database-scoped, not server-scoped, so a collection in DB_A will not resolve if the session context is DB_B.
  • Check the three-part naming convention in the client call (e.g., dbo.MySchemaCollection) and ensure the schema owner matches.

Step 2: Inspect and Correct the Client Connection String / Context

  • Ensure the client application explicitly sets the correct Initial Catalog (database) in the connection string before issuing RPC calls with XML parameters.
  • For applications using USE [DatabaseName]; statements dynamically, confirm this executes successfully before the XML parameter is bound.
  • If using ADO.NET, verify the SqlParameter for the XML type explicitly specifies SqlDbType.Xml and does not pass an unqualified or null schema collection name.

Step 3: Update SQL Server Client Drivers and Native Client Libraries

  • On Windows Server 2025 / Windows 11, update to the latest Microsoft OLE DB Driver or ODBC Driver for SQL Server, as older TDS libraries may mishandle XML type metadata introduced in SQL Server 2025.
  • Navigate to Control Panel > Programs > Programs and Features to check installed driver versions, or run:
  Get-OdbcDriver | Where-Object {$_.Name -like "*SQL Server*"}
  • Reinstall or patch the driver via the Microsoft Download Center if version mismatches are found.

Step 4: Rebuild or Re-register the XML Schema Collection

  • If the schema collection appears corrupted or was partially migrated during an upgrade, drop and recreate it:
  DROP XML SCHEMA COLLECTION dbo.MySchemaCollection;
  CREATE XML SCHEMA COLLECTION dbo.MySchemaCollection AS N'<schema XML definition here>';
  • Re-grant necessary permissions using GRANT REFERENCES ON XML SCHEMA COLLECTION::dbo.MySchemaCollection TO [UserOrRole];.

Alternative or Verification Steps

  • Use SQL Server Profiler or Extended Events to capture the exact RPC call and confirm the parameter now resolves to a valid, existing schema collection in the correct database context.
  • If the error persists, bypass typed XML schema validation temporarily by casting the parameter to untyped XML (XML without a schema collection) to confirm whether the schema binding itself is the root cause.