QuickBooks Database Server Manager is a great tool to allow organizations to work in collaboration on the same company file even when the QB versions differ. But error such as QBDBMGRN Not Running On This Computer frequently bothers the user. I came across the same and here are the steps I followed.
Open Control Panel from the Run window.
Hit on Enter and choose System and Security option.
Click on the Windows firewall and click on Check for updates.
If the Updates are found, click on Update Now option.
Wait till the updates are completed.
Restart the computer and see if QBDBMGRN Not Running On This Computer still pops up.
I hope you can fix the issue with the above steps if not, the QB support team can be contacted for a quick resolution to the issue.