This message can occur for 3 different reasons.
1. There is no active backend user account present to allow login to occur. Please contact email@example.com for assistance.
2. A security or network proxy application is blocking database communication (Sophos, Todyl, Bitdefender, AVG, Norton, etc) and needs to be disabled or adjusted. Link to URLs to allow
3. The user account used to log in is corrupted. Please contact firstname.lastname@example.org for assistance.