We have a VPN for users to connect to in order to access most of the systems they need for their work, which is installed and recomended on all of our clients. They must log in via the VPN in most cases.
Today, our SPE has started giving the 'Service Not available. Please contact you administrator'/'SPE is not configured correctly' error message, but only when a client is not connected to our VPN.
If the client is connected to the VPN, they can access PMUser, but if they cannot log in they will not be able to log in to our VPN.
PMUser works fine in a normal browsing session (regardless of VPN connection), but has stopped working in Firefox. In firefox, I get Server Error in '/PMUser' Application. (IE and Edge are fine)
PMUser also is working fine when accesses externally.
I am wondering if anyone knows where the fault may lie? We have not made any changes to our VPN or proxy recently.
I have tried:
Flushing DNS before testing SPE
KB 239613 (This gave errors in PMAdmin and did not fix PMUser, so was reverted)
Checking GPO policies to ensure the correct self-service URL is provided.
Clients are all Windows 10 with SPE 18.104.22.1681
Server is 2012 R2 running PM 22.214.171.1241 on IIS 8.
Domain controllers have the connector of the same version installed.
I'm happy to give most information I can, or try anyhting that anyone thinks could be the issue.