STATUS_TRANSACTIONAL_OPEN_NOT_ALLOWED (0XC019003F) Fix

Quick answer (for pros)

Stop the transaction that's trying to open the file, or use NtCreateFile without OBJ_OPENIF in a transactional context. If you're using SQL Server or a registry tool, switch to non-transactional file access—TxF only works on NTFS volumes without reparse points or encrypted files.

What's happening here?

I remember the first time I saw 0XC019003F—I was debugging a custom backup tool that wrapped file operations in transactions. The error means the file object you're trying to open doesn't allow transactional access. Common triggers:

• Opening a registry hive file (like NTUSER.DAT) from inside a transaction
• Using SQL Server's VDI (Virtual Device Interface) with transactional backup APIs
• TxF operations on files with alternate data streams or sparse attributes
• Any file on a volume that's not formatted with NTFS (TxF is NTFS-only)

The real issue? Windows' Kernel Transaction Manager (KTM) protects certain critical files from being opened inside transactions. Think of it as a lock that says “You can't wrap me in a rollback—I'm too important.”

Step-by-step fix

1. Identify the transaction source. Open Event Viewer (eventvwr.msc) and look under Windows Logs > System for events with source Ntfs or KtmRm. Filter for ID 0xC019003F. This tells you which process started the transaction.
2. If it's a custom application: Remove the FILE_SUPERSEDE or FILE_CREATE disposition from the NtCreateFile call when inside a transaction. Use FILE_OPEN instead, or better: open the file outside the transaction entirely.
3. If it's SQL Server: Check if you're using VDI or FILESTREAM with transactional semantics. Disable FILESTREAM transactional access from SQL Server Configuration Manager:
   1. Open SQL Server Configuration Manager
   2. Right-click your SQL Server instance, select Properties
   3. Go to the FILESTREAM tab
   4. Uncheck “Enable FILESTREAM for file I/O streaming access”
   5. Restart the SQL Server service
4. If it's a registry hive: Don't open %USERPROFILE%\NTUSER.DAT or C:\Windows\System32\config\* inside a transaction. Use RegLoadKey or RegSaveKey outside transactions.
5. Force-close the transaction (last resort):

   # PowerShell - list active transactions
   Get-WmiObject -Namespace root\default -Class __InstanceModificationEvent | Where-Object {$_.TargetInstance -is [System.Management.ManagementObject]} 
   # or for KTM:
   wevtutil epl System C:\temp\txn.evtx /q:"*[System[EventID=0xC019003F]]"

   Then kill the offending process: taskkill /F /PID <PID>

Alternative fixes if the main one doesn't work

• If you're using .NET's TransactionScope: Wrap only the specific file operations you need, not the entire block. Example:

  using (var scope = new TransactionScope(TransactionScopeOption.Suppress))
  {
      // Non-transactional file open here
      using (var fs = new FileStream(path, FileMode.Open))
      {
          // your IO
      }
  }

  This suppresses the ambient transaction for that file call.
• Check for conflicting antivirus or backup software. Some third-party tools (like Symantec Backup Exec or Veeam) inject transactions into file opens. Temporarily disable them to test.
• If the file is a database MDF/LDF: Detach the database, move it, then reattach—but do this outside any transaction in SSMS. Run USE master; ALTER DATABASE YourDB SET OFFLINE; first.

Prevention tips (so you never see this again)

• Skip TxF entirely for registry hives and system files. Microsoft deprecated TxF in Windows 10 1803. Use RegLoadKey for offline registry editing.
• If you're a developer: Test NtCreateFile with OBJ_OPENIF and a transaction handle—if it returns STATUS_TRANSACTIONAL_OPEN_NOT_ALLOWED, fall back to non-transactional open. Code snippet:

  NTSTATUS status = NtCreateFile(&handle, GENERIC_READ, &attr, &ioStatus, NULL, 
      FILE_ATTRIBUTE_NORMAL, FILE_SHARE_READ, FILE_OPEN, 
      FILE_SYNCHRONOUS_IO_NONALERT, NULL, 0);
  if (status == STATUS_TRANSACTIONAL_OPEN_NOT_ALLOWED) {
      // retry without transaction
  }

• Run fsutil transaction list periodically in production to see active transactions. If you see stale ones from a crashed app, fsutil transaction commit <TID> or fsutil transaction rollback <TID> to clean them.

This error tripped me up the first time too—especially on a Windows Server 2012 R2 box running a legacy file sync app. Once you know which files are off-limits, it's just a matter of keeping them out of the transaction scope.