Project Window Locked Up

Hi,
I opened Cubase 8 today and found practically everything in the project window was locked.
I can’t move or stretch parts at all ( audio or midi).
I can play the the tracks but i can’t move tracks up or down within the project window. I can’t stretch or shrink locators within the marker track.

I have tried it in on Cubase 8 64 bit, 8.5 64 bit, 7.5 64bit and Cubase 5 64 bit. it is the same in all of them.
I can’t work because nothing can be moved.

I have rebooted the PC (Windows 7O) 6 times and tried resetting the preferences - https://www.steinberg.net/nc/en/support/knowledgebase_new/show_details/kb_show/safe-start-mode-resetting-the-cubase-preferences.html

Any help would be gratefully appreciated.