Head scratcher here. I am using VB 5.2.18 (current version) and my Stretch host (totally updated too) runs perfectly. Fast, reliable, seemingly flawless. This host ONLY functions as an "iron lung" for all connected VM's, which lead to my workspace activities. I have a string of VM's but I only use one at a time. My Jessie VM's and I use alot of them, all run like clockwork with no exceptions I am aware of. However; ALL Stretch VM's hang/freeze after several minutes. I can use mouse clicks but keypad use, such as on a terminal or text or password entering online, etc... are simply frozen! My machine has lots of Ram. I even moved these linux VM machines to 5 Gig of Ram, plus toggled the 3D acceleration on and off. I close down VB after the VM's hang to wipe all the memory. Restart VB and then the subsequent VM's and it runs fine for a minute or so. Jessie is supported until 2020 so I can move my tasks to new machines, but where is the fun in that? Stumped here. Ideas anyone?