"Failed to open COM port handle" in QFIL (Qualcomm Flash Image Loader) typically occurs when the tool cannot establish a stable communication link with the device in 9008/EDL (Emergency Download) mode
Before diving into the troubleshooting guide, let's quickly understand what QFIL and COM port handles are. qfil failed to open com port handle
The error Failed to open COM port handle essentially means: "Failed to open COM port handle" in QFIL
The default Windows driver for EDL devices is terrible. You must manually assign the driver. qfil failed to open com port handle