iMac restarts when sleeping for more than 2 hours, why?
Since installing El Capitan my Mac has been spontaneously restarting after sleeping for 2 or more hours. The folks in Apple forums have suggested tests and removal of some software. I reinstalled the OS. The symptoms vary in frequency and intensity but are still there. With actions suggested by [redacted] in the Apple forum it got better but only for a short time; then back to usual. Nothing is lost (except the unsaved stuff) and no harm is done but the restart won't continue until I'm back and enter my password. The restart can take a long time and is annoying.
My Mac has been doing a few other weird things since El Capitan was installed too. Moving the mouse quickly sometimes cause all the icons on the desktop to disappear, like with a shutdown, but everything else works and a single click of the mouse brings them back. Moving the cursor back and forth quickly will sometimes cause a shrinking of all windows with a red line around the active window. No windows are active during this. Again, one click and it's normal again. For a while I had a lot of Safari can't open... messages but I've not seen them for a week now. It was for one web site only and could be overcome by quitting Safari and re-openning.