Event ID 5: Citrix Ticket Logon Attempted on Invalid Ticket Data

We had a problem where users where getting prompted by server for UserID and password after they had clicked an icon in web Interface. If the user completed the logon box they were still refused a connection.

The users were all being directed to the same Terminal server.

That terminal server showed a large number of
Event ID 5 - Citrix Ticket Logon Attempted on Invalid Ticket Data

It turned out that the server had been moved physically and had a incorrect IP address assigned to it. This had been corrected after the move but looked to still be causing a problem.

Rebooting the server seemed to correct the problem.