Nadrew wrote:

Looks like the code tried to access a corrupt or invalid file and choked on it.

You get my vote for that response. I laughed.

Phat T wrote:

Is there a way to prevent switching the security if that happens ?

Running a game in safe is pretty fine honestly. The only thing that can go wrong is the game can delete any files within its folder without your permission. So, you're pretty safe there. Ultra safe is literally ultra safe. It asks you for everything... Whereas safe just makes sure OS dangerous operations can't be performed. Such as wiping your hard drive as I have seen a few people try to do.

So, yeah. Only run in trusted mode for games you actually program pretty much. As for your actual error. I have no clue what's going on there. Maybe, as Nadrew said, your code tried accessing a corrupted file and couldn't. As a result, it borked out on you and produced an error. Depending on where this error originates, you may have to re-install BYOND as a whole or just renew your game's files.