As for remote session, I advised to our customer to clean install Endpoint Server on separate machine and he asked for remote session to ensure that all is working.
As I have updated earlier, I have not succeed to contact our customer regarding remote session. It seems that extension in the phone number is wrong.
The root cause of the customer's issue is port 80 that is used by Microsoft IIS.
Should we reappoint remote session or our customer will try clean installation?