due to me not having the crash file at the moment, log not available

Steps to reproduce

1. Have active windmill going at one speed
2. Have watermills going at a different speed
3. connect the two with the speed controller
4. slow the RPMs by scrolling on the controller

I had identical crashes, but i used creative motors instead. So, that works with any power source connected to both input and output.

This issue has been addressed in 0.2.3. Thanks for the report and feel free to re-open if need be.