strange issue - Fusion 8 Mac Beta

Hey there.

Mac Pro ( late 2013) Yosemite.

Installed over the weekend and was up and running.
Could go into prefs and I'm pretty sure I could do undos.

Launched today and those functions simply don't work.
I cant acces preferences and Undos don't work whether I cmd Z or even try from top menu.
Just doesn't do anything.

Nodes work fine though.

Most other top menus also don't work apart from a few like the tools menus and window menu.

I re-installed 4-5 times from scratch. deleted everything relating to it.. still not working.

something silly? Or an issue?

Thanks