After the update to MATE 1.20, MSD isn’t starting. This can be seen when launching e.g. Keyboard Shortcuts:
I’ll do some digging. A search for “mate-settings-daemon 1.20” on the Arch forums turns up nothing so far. I don’t think it’s MATE 1.20 itself as I have it running fine on an Ubuntu 16.04 system.
Edit: ah, it’s HiDPI stuff:
(mate-settings-daemon:18501): GLib-GIO-ERROR **: Settings schema 'org.mate.interface' does not contain a key named 'window-scaling-factor'
There’s a patch in Ubuntu’s Bionic packages. I’ll dig that out this afternoon.