Hi!
I have newly installed 18.03. I changed sddm-theme of known reasons 
Now there shows up a user “systemd core dum…”.
What is this?
How can I get rid of this?
Thx,
Bodiro
This sounds like something crashed. Can you configure that in the sddm settings maybe.
Couldn’t find an explanation nor settings. But I installed netrunner now in vbox and there it does not show up. So, yes, maybe something went wrong with the hardware installation.
Leszek, FYI: Now I experimented a bit, and I think, the problem is caused by activating the testing repositories. Staying with netrunner’s alone, makes no problems. Also I have not changed sddm-theme this time.
Now I have changed sddm-theme again, and no problem. So, I am sure, it is caused by the testing-repositories enabled. I will not do that again