[3dprinter-general] Bug#897000: Bug#897000: cura: crash on startup

[Gregor Riepl]

It's a bit hard to see from the stack trace  what exactly is causing the
crash. There is a mention of
/home/karl/.local/share/cura/3.1/machine_instances/AnetA8WithInit.json
however, have you tried moving /home/karl/.local/share/cura away and starting
from scratch?

I suspect this is a bug in Cura or your custom printer definiton (or both).
Can you attach the definition file?