Hi Marc, sorry for answering your questions late. By this time ı figured out that it's not about the node structure. However, if you use keyrames for a node with changing values of key (opacity) in time, In my system if ı disable/enable it repeatedly resolve crashes. Also it may be about usb or harddrive issue because i have to use the same harddisk that ı read the files from. 
 
	Anyways, it's not so important because ı use live saving mode and lose nothing at all but can be very frustrating when a client is sitting with you, and just wondered if it's a common issue and wanted to hear the ideas.
 
	Thank you all for your answers.
 
	I have micro panel, 16GB RAM,  GTX1060 and Intel - i7 7700K.