First problem I heard was around the date of 8/13 while I was still away on vacation. Kip Canfield could not access his assessments and students could not take tests. I did some testing and worked with Jeffery to prove that this was not system wide. I also found a possible work around.
I then tried rebooting the servers to see if the problem would clear. This caused the access problems to happen to not only assessments, but to every course, systemwide. I pushed out a reconfig and this caused even more problems as it would not complete cleanly. One instance of the problems was the tomcat service would not delete, so it could not be installed correctly. When I finally got the system to "config" without errors, blackboard started working again.
Then I found one really weird network issue. The database server could not reach the fileserver/collabserver. As in "ping 130.85.29.12" (from 130.85.29.13) returned "unreachable" I fixed that by removing some of the broadcom advanced features I had enabled on the database server.
The features have been running for over a year. So, my guess is that some of the recent network changes in the computer room caused this problem to show up now.
This was probably not cause of the access problems, although it would have broken the collab service.