How to Fix QuickBooks Multi-User Mode Not Working?

https://quickbookhelpdesk.com/blog/fix-quickbooks-multi-user-mode-not-working/

QuickBooks Multi-User Mode allows multiple people to work on the same company file from different computers. However, sometimes users may find that Multi-User Mode is not working. QuickBooks may remain in single-user mode, fail to connect to the company file, or display an H-series error such as H202 or H505. These problems are usually connected to hosting settings, network communication, firewall restrictions, or the QuickBooks Database Server Manager.