The 810 chipset was notorious for thermal regulation. The 0.0.3.23 DLL optimizes the data packet size and transfer speed between the PC and the phone, preventing the device from overheating or disconnecting while in Qualcomm 9008 or Download Mode. Best Practices for Safe Flashing
Ensure you have the latest LG United Mobile drivers installed on your PC. lgup-8994-dll-ver-0-0-3-23