Can you send screenshots of the problem you're having with the game crashing to email@example.com
? Maybe I can figure out what's going on based on those. Also I'd love to know the specs of the machines you're having this problem on - we're having a hard time recreating the issue this side.
There does appear to be an issue with the Unity plugin at the moment though, loads of people are getting strange crashes in Chrome in parts of the game that haven't changed in months and have been rock solid previously. So far we've gotten reports of FireFox working the best, and to be frank, I wouldn't touch IE with a 10 foot barge pole
And don't worry about the game be locked to browsers forever, as Nandrew said above, it's this way for the duration of the beta. The full game will be available via Steam and will be a standalone download. Sorry for any issues this is causing you.