ID:2711862
 
Well, I unfortunately decided to update to 514 and swap to the stable build, because "What's the worst that could happen in being updated?"
Now I cannot play space station 13, or any other game without Byond instantly crashing. I was using the Beta build originally, around 513.
Ever since I swapped to stable, I couldn't swap back to the beta, therefore making Byond almost un-usable for games.
Update: This has since been fixed. Please update to the latest version.

...

Follow the link that Gambotyde posted and downgrade to 514.1561, you should be able to play normally.

The problems facing the latest builds are rapidly being addressed and should be ironed out soon enough.