Dual boot, 16.04 udgrade ->grub-rescue prompt

I have a dual boot system with windows 10. I hadn`t touched ubuntu for about a year. Now I upgrade to 16.04 and it wont boot anymore.

I get the grub rescue prompt.

So I used the live disk to get into boot-repair. before ruing it asks if the 120Gb disk (the SSD it should boot from), is portable or not (it is not) and tells me to look at the options because it found a separate /usr on a different drive (I put that folder on a larger HD). Not sure what options to change or why it should matter.

After I run the repair it ends with an error message: Please close all your package managers (Software Center, Update Manager, Synaptic, ...). Then try again. No package managers open.

I uploaded a boot info script file created by boot-repair here: http://paste2.org/vNCXNLWe

I would be eteally grateful if someone could have a look and help out.

Chris