Unity Beast Lightmapper broken on multiple setups on blank projects!

OK So I have this odd problem. I have Unity Pro on both my laptop and my desktop, and my friend has the trial version on his setup, none of us can get Beast to render lightmaps we all get this error

Our projects are on our system drive and we have more than enough space left

Did you report the bug (Help->Report a Bug)?

Yeh we did, I guess this latest update broke Beast

Yeh I can confirm Beast is now officially broken in the latest version of Unity, I downloaded the previous version and it works. I also reinstalled Windows on my laptop (it was about time), installed nothing but the drivers, Unity. created a default new project with the default name. made a plain and a cube, saved the scene and got the exact same error.

i have this aswell. submitted a bug too. this is a pretty devastating error that i cannot explain