You cannot choose Switch to Multi-user Mode from the File menu because the option is grayed out.
The QuickBooks process in Windows may be unresponsive.
Intuit recommends 2 solutions for this problem. The first solution may solve your problem, or you may need to try both to resolve the issue. For best results, perform the solutions in the order shown.
Solution 1: Restart the QuickBooks process
If you still experience the problem, go to solution 2.
Solution 2: Restart your computer