Recursive links are easy to have and are trouble.
It is a symbolic link inside a directory back to the same directory.
Check the links in the open problem library; you can right-click on them to see where they point; delete any that should not be there (recursive)
The link below shows the trouble that a recursive link inside CAPA caused the library browser; obviously you situation is different.
just a guess - hp
"I am seeing this error box when I browse the OPL – change the chapter/subject/section, then “View Problems”, and this appears at the bottom of the page where problems are displayed. The same error box appears when I view the problems directly... It looks like the errors are the same every way I’ve looked at this – “chromatic.pm” and “color.c” and the location lines seems consistent wherever I’ve looked."
The image is attached.
Thank you again!