Hello! IIRC I always had the KER freezing issue, since the time I first started using KER (around KSP v0.18). Today I finally upgraded my PC and now everything seems to work perfectly with KER 0.6.2.2. Not 100% sure though, but my existing large ship that kept closing the flight mode KER no longer does this and I messed with my heaviest lifter in VAB adding asparagus staging, changing staging order, etc - KER keeps updating data. I had both hardware upgrade: C2D E6300 -> i5-4670 ; GTX9600 -> GTX660 and software: Windows XP x32 -> Windows 7 x64 So maybe KER is affected by some of OS component versions like .NET..?