GRUB 2 error – "fb: switching to radeondrmfb from EFI VGA"
There seems to be a problem with the radeon driver when booting. You can test a fix by doing this:


When you see the grub menu, press 'e', which will allow you to edit the entry.
Go to the line with "linux...." and look for where it says 'ro'.
After the 'ro', add 'nomodeset' (without quotes), and then boot (press F10).


If that works, you can make it permanent by editing your /etc/default/grub file, and changing the line to look like this:

GRUB_CMDLINE_LINUX="nomodeset"


Then run:

sudo update-grub


This isn't the best solution, since it seems to put your machine into software rendering. I'm hunting for a proper fix.