Just ran UE4Editor-Win64-DebugGame-Cmd.exe and the crash at 73% repeated with the following dump…
Unable to read VR Path Registry from C:\Users\ARROWHEAD\AppData\Local\openvr\openvrpaths.vrpath
Fatal Python error: Py_Initialize: unable to load the file system codec
ModuleNotFoundError: No module named 'encodings'
Current thread 0x00002b88 (most recent call first):