Not sure what is needed to fix this but i have an ASA 5520 with 2 interfaces. 1 dmz and 1 outside.
I'm using the ASA for both firewall and VPN but the problem occurs when people internally try to test the VPN portion and it directs them to the public ip address of the outside interface of the ASA. So the traffic comes in on interface dmz and needs to return out that same interface. VPN access is only allowed on the outside interface. I have the following already configured.
same-security-traffic permit inter-interface
same-security-traffic permit intra-interface