when i load the game, it goes slow, then when i play it, it says "Unexpected error occured when runny the game." And this is on Game Maker PRO. what can i do to stop it?

why do you need to stop it? It seems to me like the problem is getting it to not stop . Just kidding. Ummm, there are a few problems that could be involved here. The first one is that your game file somehow got corrupted. There isn't a way to fix this. The second is a combonation of large file size and slow computer. You will have to trim down on the file size. The third is simply just a slow computer. Get a new computer. The last thing I can think of is that Game maker just acts up some times. Restart your computer and reopen game maker.

Hope that this is helpful and insightful and ... whatever. Good luck.

what size is the room u playing in and how much objects do u have in it?
that could be the problem.