Hi @joewil09,
Multi-user and single-user mode is are great tools to let multiple people access the same company file and cut the workload in half. I'd be happy to help you switch back to single-user mode.
The first thing you should try and do is make sure that you scan the file location with the QuickBooks Database server manager by opening it, select browse, select the company file and hit scan. Once that's done you should also make sure that only the computer that has the company file on it is set up to say Stop Hosting Multi-User Access. If more than one has that option it can cause issues with the set up.
I would also try following the steps in this link to fix the most common multi user errors. If you still run into errors I recommend reaching out to our QuickBooks Desktop support team so we can look deeper into this. You can reach out to us by calling the number here.
If you have any other questions let us know and we'd be happy to help.