I had this strange problem while using directional blur.
The mac froze, it won't do anything. I could move the mouse and the arrow would move, but no program will get selected.
The option of using force quit using the key board also did not work.
I had to switch off the system manually from the power cord.
I moved to a different system ( i am working in the university system) and the same thing happened.
I am editing from a G-technology 2TB G-Drive Professional External Hard Drive with a firewire.
G-Technology 2TB G-DRIVE Professional External Hard Drive - Apple (UK)
I never had this issue before. I am working on a long project which
will take 3 years, I am on the second year.
Recently the university upgraded their machines to OS X Yosemite.
Wondering if this has anything to do with the freeze.