Does you machine home?
Some do not and if you send a home command to it, it can’t find the no existent limit switches and gives you this error…
If it not supposed to home … in Lightburn go to device settings and disable ‘auto home at startup’.
It should still be able to move around, it just doesn’t know where it is…
Check out Lightburn grbl setup…
This is a similar or maybe the same problem…