Application Fails with Error 50: Request Not Supported

A Windows application using the File Storage service returns Error 50: The request is not supported.

Cause 1: The application is configured to access files using the UNC path instead of a drive letter, but file locking is not enabled for UNC paths.

Solution 1: Enable file locking for UNC paths.

1. Click Windows Search.
2. Enter regedit in the Search field and press Enter.

   If prompted, click Yes to allow changes to your device.

3. Click HKEY_LOCAL_MACHINE, then browse to: SOFTWARE\Microsoft\ClientForNFS\CurrentVersion\Users\Default\Defaults.

4. Add a new DWORD32 registry entry for Locking:

   1. Click Edit, and select New DWORD (32 bit) Value.
   2. In the Name field, enter Locking.
   3. Right-click Locking, and select Modify.
   4. In the Value Data field, enter 1.
   5. Click OK.
5. Restart the instance.

Cause 2: The nolock option was used to mount the file system.

Solution 2: Unmount the file system and remount it without the nolock option. See Mounting File Systems for more information.