From: simonp on
After uprading to Slak 12.1, I had the same problem. But I was
able to fix it by changing the layout of .Xresources. I changed
the way I entered values to this, and it worked perfectly:

*VT100*faceName: Helvetcia
*VT100*faceSize: 18
*VT100*background: black
*VT100*foreground: white

-Simon