Since you have just updated from QB2012 there may be other issues to consider ..
The newer versions of QB desktop are tuned to newer versions of Windows - if you are still using the old PCs and/or if those PCs are running different versions of Windows then you can get some serious grief in making and holding network connections between users. Then when an active user loses their network connection without logging off first, QB may appear to think they are still logged in when they try to reconnect.
The best setup is to have all users plus any data host all using the same version of windows - for QB 2017 I think that should be Windows10. You may seem to be able to get it working on older platforms, but you then run into reliably problems as you have described.
Restarting a server, to fix one error in a program, is a terrible and impractical solution, and you are a Pro Adviser?
Intuit needs to fix the issue with their QuickBooks Messenger not terminating properly. This has been an issue for many releases now...
We have disabled the QuickBooks Messenger in all of our company files until a fix can be found.
Allow me to help and provide you with additional information regarding QuickBooks Messenger issues in QuickBooks Desktop.
It may be worthwhile speaking to our QuickBooks Desktop Team about this, I'd be interested to see if they can identify any issues on their end. I'll be available to have this case escalated to the appropriate channels so you're able to reach a point of resolution as quickly as possible
As soon as an update is received, I will be happy to update this thread and let everyone know so that you can get back to business.
For now, I'd suggest reaching out to our QuickBooks Desktop Support to have this re-investigated.
You may find the following articles helpful:
You can always get back to me if you have additional questions about QuickBooks Messenger. Have a good one.
We can configure your Database Server Manager to its default setting to get this fixed. Let me guide you through the steps.
Also, make sure you've set your firewall permission. Please refer to this article for the steps: Configure firewall security settings for Desktop.
Once done, try to log in again.
If it doesn't work, please perform the following:
You might also want to check this handy article for future reference: Account management.
Let us know if you have additional questions. We're here to help.
I freakishly have found something that has worked for me. I tried all of the suggestions above ( accept restarting the server ) and none worked. While everyone is logged into quick books, Switch to Single-User Mode .. using the messenger it will alert everyone and automatically disconnect anyone logged in. Then sign in again, as normal.
if you are using windows you can also go to Services and looks for any service that starts with name Quickbooks, right click and restart the service, i did not need to restart the computer. worked for me.