Hi @h2f ,
what method of install did you use?, if you used a DVD; did you burn it at the slowest possible speed?:
Did you format the USB stick if you used that?.
On Ubuntu 16.04, don't use any AMD drivers as they are not fully functional at the moment!:
To fix it all quicker than trying to find a solution, do a fresh install using the "Something Else" method (don't format "/home"):