I don't really understand comment #17-#18 but it looks like nobody has successfully tested downgrading Mesa yet (per comment #13).
You may have to download and install the previous version manually: https://launchpad.net/ubuntu/+source/mesa/17.2.1-0ubuntu1/+build/13388627
That's the version which was in 17.10 until 5/6 October.
I don't really understand comment #17-#18 but it looks like nobody has successfully tested downgrading Mesa yet (per comment #13).
You may have to download and install the previous version manually: /launchpad. net/ubuntu/ +source/ mesa/17. 2.1-0ubuntu1/ +build/ 13388627
https:/
That's the version which was in 17.10 until 5/6 October.