I have been fighting a Quickbooks issue for months and I think I may have finally found the solution.
I am posting this in hopes of possibly helping someone else and of maybe getting some feedback on why this fix worked.
Issue - Quickbooks Pro randomly refuses to let users open files.
Sometimes the files won't open unless no other user is in the file (even though file is open in 'multi-user' mode).
Sometimes the user can open in single user, but can't switch to multi-user.
Sometimes only solution was to reboot the server.
Problems varied from workstation to workstation.
Windows 2012 server, LAN, domain.
Quickbooks Pro 2013 installed on server.
Quickbooks Database Management Server running on server
Quickbooks data files stored on server hard drive.
Workstations - Windows 7 and Windows 8.1.
All firewall and anti-virus settings appear to be correct and allowing proper ports and apps to run.
Notes - Normally in a multi-user server install environment such as this, you don't even need to install full Quickbooks on the server.
You can just install the Quickbooks Database Management Server.
I started with this configuration, but I was having so many issues, I went ahead and installed the full Quickbooks app on the server to help me deal with enabling/disabling multi-user hosting.
The Fix -
What seemed to finally fix all the issues was to simply open up the Quickbooks application on the server and leave the app running. No Quickbooks data file is open on the server, just the app is open.
The Quickbooks Database Management Server is still running as well.
Can anyone think of any reason why this fix would work?