Black & Red Chinese 60W. Ruida 6442G controller. Was having intermittent problems with my computer communicating with the Laser (USB connection). Did the update to 9.21 and now having real issues. Getting a lot of “Lightburn not responding”, the software will not communicate with the laser - get both “not connected” and “ready” messages, but no connections. At one point, it shut my computer down and into a restart.