Hello der_bud,
cleanup is neccessary, because in April intel had tagged the driver in git as version 2.99.918 but withdrawn to 917 later.
If you experience any problems with the intel driver we suggest to purge and install the intel driver,
apt update && apt purge xserver-xorg-video-intel && apt install xserver-xorg-video-intel
or just downgrade to the current version, e.g. :
apt install xserver-xorg-video-intel=2:2.99.917+git20160706-1
greetings
musca