problems could be the cause of your inability to can’t access the company file in multi-user mode in QuickBooks. To fix the problem, make that QuickBooks Database Server Manager is operating, the file is on the server, and all users have the appropriate access. You may reach a professional at 1.855.738.2784 if you need assistance with QuickBooks.
https://accountinghelplineus.hashnode.dev/cant-access-the-company-file-in-multi-user-mode-in-quickbooks