BusyBox ALERT! device not found

Hello Everyone,

Intro
i know, there are at least 1000 posts and questions and at least 12 bug reports at Ubuntu regarding nearly the same problem, but none of them are working (and to be honest are not 100% as my problem)

Problem
I freshly installed ubuntu 16.04 via a live-usb stick. As expected, the usb starts smoothly i run the setup as I always did since I'm using ubuntu and no problems happend. Restart to fresh ubuntu results in:

Check root=bootarg cat /proc/cmdline
or missing modules, devices: cat /proc/modules ls /dev
Alert! /dev/disk/by-uuid/xxxxxxxx-xxxx-xxxx-xx$ does not exist.  Dropping to a shell!

ls /dev

cat /proc/modules

#GRUB_DISABLE_LINUX_UUID=”true”

Check root=bootarg cat /proc/cmdline
or missing modules, devices: cat /proc/modules ls /dev
Alert! /dev/sda1 does not exist.  Dropping to a shell!

• Before Installation of Ubuntu i had Mint 17.3 (keel version 3.19) booted as a charm but was not only able to init my wifi with ugly hacks - This is the reason for the desired keel update but upgrade the keel of this distro killed it.
• Alongside, on /dev/sda2, i have windows 10 - boots like a charm
• As Ubuntu 16.04 (keel 4.4) didn't work, i freshly installed Ubuntu 15.10 (keel 4.2) - same problem here, the devices are not found by the keel - although by grub and the live usb
• When writing manually into the grub console to show all messages there is only one line which says "ACPI probe failed" - I googled and it is said, this is no problem at all..