To fix the QuickBooks error 6123 while restoring the company file, you need to change the hosting settings of the QB application. The steps that you need to perform are as follows:
- Go to the QB Desktop application and open the company file on your screen.
- Then, move to the File tab and switch it to single-user mode if it is running in multi-user mode.
- Alternatively, again go to the File menu and opt for the Utilities option, followed by the Stop hosting multi-user Access option.
- Now, again you need to host the multi-user access by moving to the File menu, followed by the Utilities option, and choosing the host multi-user access option.
- Then, hit Yes if a permission box appears asking you to switch to multi-user access hosting.