| Problem | Likely Cause | Fix | |---------|--------------|-----| | “LightBurn.exe is not a valid Win32 app” | Corrupted RAR or incomplete extract | Re-extract with 7-Zip, re-download archive | | Crashes on startup | Missing VC++ runtime | Install Microsoft Visual C++ 2015-2022 | | License error / “Trial expired” | LightBurn phoned home | Block app in firewall, or use hosts file redirect (not recommended) | | Laser does not move | Wrong COM port or baud rate | Check Device Manager → Ports, set baud to 115200 or 250000 | | No “LightBurn1706RAR work” after crack | Antivirus deleted patch file | Restore from quarantine, add exclusion folder |