Desktop notifications no longer appear

Hi - I'm on Ubuntu Mate 21.10 and I can't figure out what I have done wrong.

My Notifications no longer work.

I get the attached error ( Yes I have looked )

Error while displaying notification. Error calling StartServiceByName for org.freedesktop. Notifications exited with status 1


I think I fixed it.

Oooops! i had installed i3 and plasma and hadn't removed all.

Now I have. Back to normal with Notifications.