I upgraded to Yosemite and the latest PD last night. I worked all day in both with no problems. Tonight, however, is another story. Now, unless I am actively using a Windows app, my VM goes to sleep within a few minutes. Even if I am using Finder to copy files between the VM and OSX! The drive will be there one second and gone the next without any warning. I checked my power management settings in the VM and they are set to the Parallels configuration with "Never" selected for when to go to sleep. Where else should I look?
Please try to disable 'Pause Windows when no applications are open': In VM configuration, uncheck that option in Options -> Applications.
