HTTP 401 Auth Error after changing PSE

Evening,

We've had to change the PSE of a system and that linked to 'Easy Document Management System'. I'm struggling to find information on how the authorisations works and what needs to be set up / exchanged with regards certificates if anything. The PSE has the same CN as before - I'm just wondering if anyone else has done this, set it up and knows, or even knows where the documentation is for Easy.

Have had looks around but searching for 'easy' brings up a lot of hits.

Many thanks,

RF.