long ago i messed with the skulk materials to make a reddish skulk with red eyes. i copied the skulk model and materials and simply made a new folder for the original skulk model called skulk_old. then i put my reddish skulk in under the original name so the game would render my skulk and i could run around as my red skulk.
later when the game patched it rewrote my assets and my red skulk was gone (no big deal, it didn't go over well on the forums anyway) so i went in and deleted the skulk_old folder and its contents because i didn't need them anymore.
I must have still had the prop skulk model from the skulk_old folder in my level somewhere because when i load my level i get:
Error: Couldn't open file 'models/alien/skulk_old/skulk.model
so since i don't want this error anymore and the folder isn't there, i guess i'm asking how i find this invisible prop in my level so i can delete the reference and kill the broken link error.