A client was using Quickbook Pro 2015 on Server 2012 Essentials. Every time I would run the QuickBooks database Manager I would receive an error similar to the following:
Windows firewall: Disabled exceptions not defined
Network Diagnostics: Failed. Resolve errors and Retry!!
The above errors would persist even if the Windows Firewall was active or not. I had already added the necessary ports for Quickbooks in the Windows Firewall. You can find the necessary ports here. The necessary ports for Quickbooks 2015 are 8019, 56725, 55363-55367. Even after adding the above mentioned ports I was receiving the same Quickbooks Database error. After troubleshooting this issue for some time, I realized everytime that the Quickbooks database manager would run it would add an additional rule to the Windows Firewall. 
The weird thing was that you could use Quickbooks even though this error was displayed in the Quickbooks Database Manager. However, nobody likes to see errors.
I did a deeper drive into the issue. This is what I found.
I opened the Windows Firewall and found the following blocked ports:
2017-06-22 09:27:40 DROP UDP 169.254.4.254 255.255.255.255 58070 4994 51 – – – – – – – RECEIVE
2017-06-22 09:27:43 DROP UDP 169.254.4.254 255.255.255.255 58070 4994 51 – – – – – – – RECEIVE
2017-06-22 09:27:46 DROP UDP 169.254.4.254 255.255.255.255 58070 4994 51 – – – – – – – RECEIVE
I didn’t find these ports documented anywhere on QuickBooks support, so I decided to add those ports in the firewall. 
Once I added those ports I ran the Quickbooks Database Manager everything came back successful!
If you are having the same error above, try adding the ports I have mentioned in this article. If those ports don’t work, check your Windows Firewall logs and see if the Quickbooks Database Manager is using alternate ports. If you need help configuring the Windows Firewall logging, check this link.
I hope this helps. This was posted by techspeeder.
So how do you look up to find out what ports are being blocked by the firewall? I just added those ports to the QBs rules and it still shows that either the firewall is blocking Quickbooks (Firewall On) or that the firewall exceptions are wrong (Firewall Off). So confusing. You would think that turning it off would stop the errors, but it doesn’t.
Man I feel your frustration. QB can be such a nightmare some days. I may write a blog post about how to enable Windows Firewall logging and how to read the logs. However, until then this article should give you enough info to get by: https://www.howtogeek.com/220204/how-to-track-firewall-activity-with-the-windows-firewall-log/
On the server that was giving me this issues, I also have the QB Services running as the local system account. I don’t know if that helps or not. Good luck
We were having multi-user mode errors, the Database Manager was failing on the network test so your post came up first in Bing. All my ports were open to a number of Quickbooks EXE’s and still failing. So I just deleted all the Quickbooks entries and ran the Scan again. It created new rules and now seems to work, Time will tell with this because we had it working after a restart 4 days ago now it was back. Quickbooks “Server” is a joke!