As far as the crash goes I'm not sure what would be causing that, although it could be one of the parts your using as some of them have issues.
Gauntlet made a tutorial for Grouped components that I found rather helpful and I would recommend checking it out if you haven't already, its possible you're doing one minor thing differently and it's causing an issue.
https://www.youtube.com/watch?v=L8Dj9uaVIO4&index=2&list=PLVA5Lf10pstMfYckhKGNE2YjlAtbRaTD1
I wish I could be of more help, good luck 
