Well, this is rather a rarity for me. It’s been a long time since LightBurn crashed on me.
I had some small vector objects on screen and I was removing a few shapes and modifying a few others with the node edit tool. I deleted a bunch of nodes and then decided that I had removed too many so I hit ctrl Z once to go back a bit. Hit ctrl Z a second time and bing, LB was gone. It just instantly closed up shop and went away with no error message. 
I reopened it and had lost a small it of work but I went back and finished up with no further problems.
It wasn’t a big deal, but it was a surprise and I figured I better report it.
Linux Mint 19.3, LB 9.09, SVG file imported from Inkscape…