Thank you for sharing the detailed information about your concern, VassiliTN. I'm here to explain how the different modes of QuickBooks Desktop (QBDT) work.
You're correct that a user will sometimes be required to be in single-user mode for application integrations and some other particular procedures.
Furthermore, if you attempt to turn on to Single-user mode when one of the multiple users is using the QuickBooks company file already, there might be the chance to get an error message saying that the mode cannot be changed until all other users are logged out.
In order to switch to single-user mode, you must ensure that no other users of the company file have any ongoing data processes initiated within the program. This simply means that you must ensure that all users, except yourself, are properly logged out of QuickBooks accounting software before switching modes.
Additionally, you can check out this article to learn more about what you can do in the multi-user mode: Features available and tasks you can perform in single or multi-user mode in QuickBooks Desktop.
If you have any further inquiries regarding your user modes in QBDT, please let us know by leaving a comment below. The Community and I will be here to help you. Have a good one.
