Backup for Files - Application freezes when adding folders or using Visualize

Written By Tami Sutcliffe (Super Administrator)

Updated at March 31st, 2021


Clicking the Add or Visualize buttons on the Folders page will bring up a dialog, but the backup manager application stops responding and appears to freeze or hang.


This problem can be caused by a problem in the Microsoft SMB version 1 implementation of opportunistic locking (mrxsmb.sys). If a stack trace of the main thread of the backup manager using Microsoft Process Explorer while the GUI is unresponsive includes mrxsmb.sys, this indicates that the opportunistic locking problem is the cause.


Microsoft describes how to fix the issue by disabling opportunistic locking in KB 296264. To summarize, the fix involves changing the value of a registry key and then rebooting.

(WARNING!!! Editing the Registry improperly can prevent your computer from booting!!!) To try the fix, follow these steps:

  1. Start. run. regedit.
  2. Navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MRXSmb\Parameters
  3. Double click the OplocksDisabled value (should be a REG_DWORD value) and change the value from 0 to 1.
  4. Reboot

If you still encounter difficulties after following these steps, please contact technical support.