"Phantom" EPDM reference - can't figure out where it came from or how to remove

We've got a couple of parts in our EPDM system that show "where used" like this, but the references cannot be seen on the other end, and for the life of me I can't figure out how to remove them.   Any clues?  (see the "greyed out" line)

SolidworksSolidworks Pdm enterprise Pdm