Failed keyboard-interactive

I have a user that seems to be getting kicked out of his session. I have the Time out set to 30 Minutes, so it is not that. The log shows "Failed keyboard-interactive "
What does this mean?

Which product are you referring to please?

Using a CM8 as master to 8 Clustered CM 32 and 48’s. Ver 1.8.0

We need to spend some time troubleshooting. Please submit an online support request at:

http://www.digi.com/support/eservice/eservicelogin.jsp

Thanks