2020 Brood War era material, unverified. On Remastered many of these no longer crash, but the broken graphic remains.
While editing images you may find an unrelated rock appearing above a unit. It is not a bug but a default: an image whose iscript offset is 0 runs whatever sits at entry 0, and that entry draws a rock sprite above the unit.
The fix is to point that image at a real iscript. Do not leave it pointing at nothing: nothing does not mean do nothing, it means do entry 0.
Pointing an image at a script that asks for a frame that does not exist gives you a dolmen - a blank frame is the sign, and it is crash list #5. Giving it a script with no destruction motion makes sprites accumulate until the game crashes - #10.
The iscript ID list