eyedropper tool refuses to recognize it...
I've had this with things that are extracted incompletely like cars or things from other type lot zones perhaps sometimes too. Definitely a little flag somewhere needs to be thrown.
I got this just the other day with a cloned turkey dinner. I deleted it and forgot it was saved in one of my properties so when I loaded the game back up (even with the file back out of recycle bin) the darn turkey dinner turned into the white-butcher paper wrapped turkey package and would not budge no matter WHAT I did! I had to bulldoze probably but I needed to reinstall at the time anyway, so I just did that, but geez.
SPECIFICIALLY what causes... I dunno, maybe someone will come and tell us both but I feel your pain.
Deedee