That Error Code 0XC0000212 – Here's The Real Fix
You're staring at a database error that says the transport didn't find a matching transaction token. Frustrating, right? I've seen this on SQL Server 2016 and 2019, especially when a linked server query times out or a client app drops a connection mid-transaction. Here's the fix that works.
Step 1: Kill the Stuck Process
First, find the process that's holding the orphaned transaction. Open SQL Server Management Studio and run:
SELECT session_id, transaction_id, status FROM sys.dm_tran_active_transactions WHERE status = 'ROLLBACK_IN_PROGRESS';If nothing shows up, check for sessions that are blocking. Use this:
SELECT session_id, blocking_session_id, wait_type, wait_time, wait_resource FROM sys.dm_exec_requests WHERE blocking_session_id > 0;Once you see the session ID that's hanging, kill it with:
KILL 55; -- replace with the actual session_idHad a client last month whose entire print queue died because of this. A single orphaned transaction stopped all inserts into their inventory table.
Step 2: Clear the Transaction Queue
If killing the session doesn't clear the error, the transaction log might be corrupted for that one transaction. Run a CHECKPOINT to flush the log:
CHECKPOINT;Then shrink the log file if it's bloated:
DBCC SHRINKFILE (YourDb_Log, 100); -- target size in MBThis forces SQL to clean up any incomplete transactions that are stuck in a pending state. Don't shrink your data file though – only the log.
Step 3: Restart the Transport Service
If the error persists, the transport layer (like a linked server or Service Broker) needs a kick. Restart the SQL Server service. On a production box, schedule a quick restart during low usage. I had a case where a restart fixed the token mismatch instantly – the transport queue was holding a dead transaction reference.
Important: Always backup your transaction log before any major cleanup. You don't want to lose data if something goes wrong.
Why This Works
The error 0xC0000212 means the transport layer (like SQL Server's network interface or a DTC coordinator) received a transaction token that doesn't match any active transaction on the server. This usually happens when a client disconnects mid-commit or a timeout kills the session before the transport knows about it. By killing the session, you remove the orphaned transaction. Clearing the log ensures SQL doesn't keep trying to roll it back. Restarting the service resets the transport state.
Less Common Variations
Sometimes the error pops up in Windows Event Log, not SQL Server. That usually means a distributed transaction (like across two servers) failed. Here:
- Linked server queries: If you're using linked servers, make sure both servers have the same MSDTC settings. I've seen this when one server uses 'Allow Inbound' and the other uses 'No Authentication'. Set both to 'Allow Inbound/Outbound' with mutual authentication.
- Service Broker conversations: If you're using Service Broker, check sys.conversation_endpoints for conversations stuck in 'DISCONNECTED_INBOUND' state. Use END CONVERSATION to clean them.
- MSDTC timeouts: Increase the transaction timeout in Component Services. The default 60 seconds is too short for heavy ETL jobs. Set it to 300 seconds.
Prevention So You Don't See This Again
Three things:
- Set connection timeouts on your apps: Most client libraries have a 'Connection Timeout' property. Set it to 30 seconds. If a query takes longer, the app will drop the connection gracefully instead of leaving it hanging.
- Use explicit transactions with error handling: In your stored procedures, wrap transactions in TRY/CATCH. If something fails, roll back the transaction before the client disconnects.
- Monitor for blocking sessions: Set up a SQL Server Agent job that runs every 5 minutes and logs any session that has been blocked for more than 60 seconds. Catch it early before it becomes a problem.
I had a client who ignored this and ended up with 150 orphaned transactions across three servers. Not fun. A little prevention saves you from a late-night call.