I'm using VMware Horizon Client on a Apple Mac for connecting to Windows desktop at work, and frequently encounter screen freezing of the Horizon Client.
This seems to be triggered by swiping left/right to switch between OS X 'spaces' and view a local screen on my Mac.
When I return to the Horizon client window it is unresponsive. I think it gets confused by switching 'spaces'
What I find interesting is that mouse clicks seem to still be processed in the background
because when I finally get back to my remote windows desktop, it was updated.. For example clicking to close a window actually closes it in the desktop,
It's just the Horizon Client does not repaint again. I use a 3 monitor setup and the horizon windows on the other two monitors usually continue to function.
To recover, I previously restarted the client each time which was painful, but I found an easier workaround by bringing up the menu bar and selecting CTRL-ALT-DEL menu item..
All screens will go dark/ or to the remote Windows screen that asks to lock/change password/etc.., except the frozen one.. but if I swipe left/right again to switch 'spaces' (on the frozen screen or maybe on one of the other monitors, i don't actually remember the exact sequence that works..) I can usually make it come back to life.. then I just hit 'ESC' key for windows to return back to my windows desktop where I left off. Hope that helps someone.