I've had a strange problem for some time now. I can't reach the SSL VPN portal, nor does an SSL VPN dial-in from outside work anymore. As far as I could understand, the configuration has not been changed. It just stopped working right away. At first I suspected the upstream AVM FritzBox to be the culprit but all other external accesses to or through the Fortigate still work without problems (e.g. NAT rules like FTP access from outside without VPN or an OpenVPN dial-in to an internal OpenVPN server). Internally I can also access the SSL VPN portal site without any problems (via the internal interface, I have two interfaces configured in the SSL VPN portal 1x internal 1 external).
What could be the problem? I simply can't get any further at the moment.
Fortigate 60F, FortiOS 6.2.2