woo someone else has this!!!

(its a good thing because its not just me)

Again, as I said in the other thread. The repo is :
Open spine (maximized, non fullscreen)
Switch to animate mode (maybe redundant step)
Alt+Tab to another program to replace focus and visibility of spine (minimise button in spine is not pressed) (in my case this was visual studio)
Alt+Tab(hold) +Mouse select Spine (may need to do this multiple times, my experience always < 3)
Freeze.

And @AlstonA, You should disconnect your hdmi/dvi/whatever cable to your monitor, and reinsert it, in my experience (2 monitors) it sometimes forces spine to unfreeze.