What does it mean when I get needs more overshotting message

It turns out that’s the cryptic message telling you the material you’re engraving is too close to the side of the platform.

When the laser head travels across the material during each engraving pass, it requires some room on either side to speed up and slow down. When the controller calculates the motion, it also takes into consideration whether it will whack into the side of the machine and refuses to make the move under those conditions.

This usually happens when the material is too close to a side, but can also come from configuration problems:

Excessive overscan settings
Too-low acceleration
Too-high speed
Incorrect axis length
The LightBurn preview will show the overscan region, so you can get an idea of how much space you must allow on each side before you start the job.