OMV installation problem

[Rheinwasser]

So, I want to install OpenMediaVault on my little AM1 server. I am installing from an USB stick which I created using Unetbootin to an ssd.

Everytime I start the installation it fails to install grub. I fixed this by opening a shell and entering these commands:

chroot /targetgrub-install /dev/sdcgrub-updateexitexit

After that I chose to continue without bootloader.

Now everytime I boot it tells me 

minimal bash-like line editing is supported grub

and I can enter something. I don't know what to enter or what I have done wrong.

Thanks a lot!