Okay, the fact that no one has pointed this out yet is pissing me off, so here goes:
BYOND is not going to be as good as a paid-for product because the people who make BYOND do it as something on the side. Fucking duh, man. The people who make RPG Maker are employed by a company to do so, and they are paid a salary for their work. Asking BYOND to get the same quality out of that is insane.
Game Maker started out the same as BYOND too. Totally free, and remained totally free for years.
Then it added a "donation" button, but that was optional. At this point Game Maker had everything it has now, except for a few bug fixes, preformance improvements and one or two new features. The difference between using Game Maker version 5 and 7 that you might notice is one works on Vista, the other doesn't.
Just another excuse if you ask me. Game Maker had the exact same situation as BYOND for a very long time (actually, BYOND had more than one person working on it, so it had a better situation) and only recently did Game Makers situation change, and nothing about Game Maker has changed since then.
Like I said, BYOND could (and should) be comparable to programs like Game Maker, but it isn't.
Also, there is a bug in the newest version of Game Maker that causes application errors like you are getting.
Chances are the games you are playing are using MP3s, and your default MP3 playing program has been changed to something not windows media player. This basically makes Game Maker games that use MP3s crash.
BYOND is not going to be as good as a paid-for product because the people who make BYOND do it as something on the side. Fucking duh, man. The people who make RPG Maker are employed by a company to do so, and they are paid a salary for their work. Asking BYOND to get the same quality out of that is insane.