I hadn't installed the amd64-microcode package. So that's done now.

Meanwhile, I had another crash, while avoiding playing video files. During several failed boots the kernel hung on a message complaining about ECC memory signatures not present (it's non-ECC DDR3). I've now taken out 3 RAM sticks so now running on 1x 8CB. Playing mkv video finished fine, am mp4 crashed after a while (ca 4 min in). I've also removed the nVidia GPU, so now on the R7 APU.

Stress looks interesting, I'll install it and see what it can do.

Devuan doesn't use ppa's, it's an Ubuntu thing. Devuan is not based on Ubuntu (and never will be) so you'd need to add the repository to /etc/apt/sources.list manually.

Sudo is a typical Ubuntu-base prefix, on Debian and Devuan by default* you don't need sudo, just su and you have root permissions. Achieve the same on Ubuntu with

sudo su

Now skip the sudo prefix from the above commands.

*this depends on whether or not you've set a root password during installation. If you have, sudo is installed, but disabled for your user. (installed because other programs need it anyway). Technically, if you set a root pw, your regular user is not added to the /etc/sudoers file.

Does it include a patch package to undo the horrible change in su behaviour introduced in the 3.0 release?

"Freedom of speech" doesn't mean you can say absolutely anything, anywhere, anytime. Your "freedom of speech" ends where it encroaches on freedoms of others. Disagreeing is fine, as long as it remains respectful and civil. These principles of civilisation have been trampled by certain groups and individuals in the past and exactly that is now being addressed.

As this subject has the potential to explode I'd prefer to keep it at that.

Try

su <user>

Then hit enter. Only then do you provide the password!

If that doesn't work, do

id <user>

This should provide you a list with the groups your user is a member of. Should that yield a negative result, you may need to delete the user from your system and start again. Report back when you get that far.

That would make sense and is much preferable to a DDOS attack

Alas, I'm not on IRC so didn't see that. Hopefully the team will remember to post a warning on the forum too on the next instance.

Thx!

Find and install the mate-desktop meta-package in Synaptic. Mate and XFCE can happily co-exist, there's no conflict so no real reason to remove XFCE other then saving space on your virtual drive. If you still want to remove XFCE, there's an xfce-desktop package as well, see if that's installed then purge it and all of its dependencies. Synaptic is a smart tool (or rather, the underlying .deb packages) so it'll complain when you want to remove a package Mate relies on.