after upgrading to 188.8.131.522, our PRTG-Installation fails to startup. Service "PRTG Core Server Service" tries to start - but not finishes startup. In serverlog, we can see, that all ports on the second IP of this NIC are occupied.
CheckPortIsFree: Port 8443 on <2nd ip> is occupied.. Waiting, retrying.. CheckPortIsFree: Port 8444 on <2nd ip> is occupied.. Waiting, retrying.. ... CheckPortIsFree: Port 8584 on <2nd ip> is occupied.. Waiting, retrying..
Then I tried to install from this https://kb.paessler.com/en/topic/83364-update-from-18-1-36-not-possible but it did not solved my problem. Log filled up with same checkportisfree message.
Then I deleted the 2nd ip from my nic and restartet services - and it worked.