Hello,
Can you give more details about the console you are trying to access? I do manage a MiVoice Business system, but I'm not putting 2 and 2 together on what exactly your trying to access..., but I'm going to take a leap here and guess that you might want to check on the licensing of the user that you are getting the issue with, this can be part of the problem.
Can you try login in and accessing the same system form another computer?