After an upgrade from version 188.8.131.522 the core server won't start anymore. We get an message that the webservice has an issue starting.
In the PRTG Core Server Log, a message is displayed:
11/04/2017 14:17:40 Ticket ReadHeaders Exception: List does not allow duplicates ($07B3)
11/04/2017 14:17:40 Startup: Problem during startup: List does not allow duplicates ($07B3)
We already tried to replace the config file wich didn't help