Welcome back, @jk8.

The investigation of the multi-user errors was already resolved and tagged as closed last March 2022. Let me share the resolution given to resolve the issue.

This issue was resolved by updating your QuickBooks Desktop to R3 or higher release. If it doesn't work, you'll need to reinstall QuickBooks by running the installer as Admin. 

You may also need to open the Database Server Manager through the start menu and run as an admin by not opening through the QuickBooks Tool Hub.

If you get the same result, I recommend contacting our QuickBooks Support Team. This way, they can further check on this issue and provide in-depth troubleshooting steps to get this resolved. They can also reopen the investigation if other users are experiencing the same.

Come back to this post and let me know how it goes, @jk8. I want to make sure you're taken care of.