Pixhawk 4 USB driver error

I have attempted to test the waf build environment by rebuilding the current version of ArduPlane. When I flash it to the board through the “load custom firmware” feature in Mission Planner my PC no longer recognizes the COM port. When I plug it back in it assigns the board to a different COM port (1,3,etc) and when I try to connect it yields the following error:

When I load the default firmware again through Mission Planner the board connects as normal on COM4. Should I use QGC or another method of uploading firmware? It seems this is related to USB drivers…

If you’re using ArduPlane and MissionPlanner you’re probably better off asking in the ArduPilot forums since this is the PX4 forum.