CANDLE does not read the file. I know it’s a text file. I wonder if LB is adding something that CANDLE does not recognize. My test file is just a simple circle.
CANDLE shows the command lines but does not draw the object.
Candle is extremely outdated and a bad tool. If you are controlling a CNC, try gSender. Much better. I didn’t test if it can handle gcode without z values, but I guess so.
Fully agree on this one, Gsender is great (and free). When you are looking for a good 2D program to design your CNC work, try Carbide Create, version 622 is a bit older but also free and has a great option to save the GRBL files including toolpaths.