Thank you very much. Apparently a batch got created without dates. I've never seen that before, however to delete that batch: All the way to the left of the table you sent a picture of, there is row numbers for every entry, right-click on 6 and delete it. Then click Write Changes At the top to save the database.
If you could then re-add this batch and try to reproduce this problem that would be great.
I'll definitely keep my eyes open for this bug, and I'll see about adding failsafe functions to the next release.
Thanks for your help.
Well it happened again. Another batch created without dates. I followed the above instructions and fixed the issue