Had an error at 1600 lines in, how do you start on a specific line?
You can manually edit the g code file to delete the lines before the line where the problem occured, there may be some 'header lines you will need at the top of the file that do things like start the spindle, set the work offset, set the units etc - these you will need to keep.
In my case using Fusion 360 it generates this code:
G90 G94 G17 G91.1
G53 G0 Z0
The “Nxx” are line numbers and are not really needed, the G, S and M commands are the important ones. The next line is the first “movement” to the starting point, this is where you would delete the lines to the one you want to resume at, these will be G0, G1, G2, G3 (movement) commands.