Hi,
 
	I´m playing x-plane 10 on Mac 27" (mid 2015) on yosemite
 
	It was all good first when I bought the computer in august 2015 but then it started to crash a lot and specially when playing video on youtube (use it
 
	for looking for tutorials) If I wasn´t playing youtube it crashed anyway when flying longer than 40-50 min - Yesterday I upgraded the memory from 8GB to 16GB and
 
	I flew from Geneva to Barcelona with tutorial playing in youtube on and off, without crashing - I couldn´t believe it - just like a new computer
 
	 
 
	Today I was flying again, just 10 minutes from take-off, opened youtube and it´crashed again - it´s always the same, computer freezes with hickup sound (stuttering) for 10 seconds
 
	until Mac restarts.
 
	 
 
	Any ideas what can cause this?