Most recent post not showing in 2 categories?

When I look at the main list of discussion board topics, two of those topics do not have anything in the "newest post" box.  That box (cell) is just blank.

One of the affected topics is "Hormonal Therapy."  For quite awhile now, one particular thread has been at the top of the list of threads for that topic.  The thread has only one post--the one that started the thread.  But the post cannot be opened or read--when I click on it, I get an "oops" message indicating a technical error and a statement that BCO is working on the problem.

This morning I noticed a similar problem in the "Chemotherapy" topic.  Someone created a new thread, but that post cannot be opened.  Clicking on it brings the same error message I mentioned above.  The faulty thread stays at the top of the chronological list, and there is no "newest post" listed for the "Chemotherapy" topic on the main topic page--just an empty box.

These glitches don't interfere with the ability to read all the other posts in those topics, but it is frustrating to see that empty box instead of the subject of the most recent post.

Did any of that make sense?  I've been trying to figure out how to explain this problem.  Must be the chemo....

otter