About a year ago we installed the SDL Licensing Server on one of our servers and added our SDL Trados Studio 2015 Professional (Network SN) licences. It worked without issues but it suddenly stopped - we do not see any licenses (0) in pool and they are not accessible from our computers which used them regularly in our team.
It happened after we have added new antivirus and anti-malware software at the license server. It should not be related in general, but I prefer to mention it even if the license server seemed to work the very next day.
What should we do to have the working server again?
Is it enough if we try to add to it the activation code we had used originally?
Will it not be seen by SDL license registers as kind of violation?

Or we should uninstall the server and install it again (maybe there is some updated install version)?

Thank you,
Grzegorz