, The issue usually arises when QB Desktop tries to connect to the company file but is unable to do so for one of the reasons given below.
On either the workstation or the server, the hosting settings are incorrect.
In QuickBooks multi-user mode, the firewall system may be blocking the complete communication line.
It's possible that you've made some DNS changes that aren't acceptable.
QuickBooks is unable to connect to the other machines on the network due to some general network configuration problems.
An error happens when a company file is damaged or corrupted.
When the QuickBooks database server manager is not functioning on a Windows PC, the issue also appears.