I made a stupid mistake.
I accidentally set the SSL from 443 to 465; now the web interface does not work.
Unfortunatley, I previously also removed the Device button from the display panel so I cannot do a factory reset to correct this.
How to connect with the webserver now OR perform a factory reset?
Go to Solution.
Allowed port 465 in Firefox. Then the webinterface was reacheable and I could reset HTTP SSL to 443.