This is a new warning, and I’m going to add a switch to disable it for those with no limit switches installed.
When you click Start, LightBurn asks your controller where it is, and if running the job from there would take the machine beyond the size you’ve told LightBurn your machine is, it reports this - it generally saves people from lost work, but it’s annoying if you have a machine without homing enabled. The next release will have a fix.