I have no solution to this problem, but I wanted to chime in and say that I’ve experienced this too. Twice I’ve been using the red laser and everything is working correctly, then I change the file in illustrator somehow (like move the vectors around or add a line) and the vectors are no longer picked up when sent to the laser. The file is being sent (the file name shows up on the laser), but it shows as blank, even when the colors are right and the laser settings are unchanged. No clue whats causing it. My workaround was to save the file as SVG and open it in Corel and print from there, which seemed to work for me. Annoying issue, and restarting the computer and the laser didn’t seem to fix it. It only seems to be a problem in illustrator.
Anyways, maybe that advice will help in a pinch so you don’t need to waste all your laser time, but if someone knows a real solution or what we are doing to cause this problem that would be useful.