Instructors have reported that after editing a homework set (for example, deleting, adding, reordering problems in a homework set), the path names suddenly disappear (appear completely blank) on most problems in the set. This happened yesterday; 10 out of 12 problems in a particular set resulted in blank path names (and were not manually deleted or blank to start with). We have seen this a handful of times before, but it's been at least 5 years since the last report.
We have not been able to replicate. In the case yesterday, the instructor reported reordering problems just before it happened.