This error seems to happen in multiple places, which is quite interesting. I haven’t tried to publish after this error but I sure hope it doesn’t brick the island. I repro’d in a few steps for NPC spawners, and it can happen on HUD message devices as detailed in the linked post. Since the editor didn’t hard crash I assumed it was ok to keep making the island.
The one I reproduced and yours are the same, error on line 493. The OP to the post I linked had the same error category but unknown identifiers, so I posted how to repro the error we have run into[493] in hopes it helps hone in on their exact error. Since it didn’t hard crash and the project validated while still pushing changes, I just kept working until I saw that post. Up voting both though.