So I just upgraded to today's release... I'm in Coherence mode and am going to the view menu, but the Coherence option reads "Enter Coherence" and is grayed out. "Enter Full Screen" is available (it is usually grayed out when in Coherence), but selecting it does nothing... In short, I appear to be Stuck in Coherence as no option is available that allows me to exit Coherence...
I seem to have been able to break out of it by uninstalling parallels tools, then rebooting and re-installing it... Hopefully it was a one-off fluke...
Thank you for bringing it forward. Usually when Parallels Tools are updated VM quits Coherence and enters Windowed view itself. If the issue reoccurs, generate a problem report in Coherence and share it with us.