I'm struggling to boot Ubuntu Studio, installed on my external SSD. I've got an USB Stick witch I can use to start the live system. I tried to run boot-repair, but it didn't solve the problem.

Before I run boot-repair at least the ultrabook seemed to try and start the system on the external ssd but failed and the windows bootloader(?) Told me something like: "there's an invalid system on the external drive"

Here's the link from the boot-repair: paste.ubuntu.com/7420589

Thanks for helping me in advance.