crash when saving a binary file with eKinematic flag

I have a simple phys xml file that I generated from a static box. Reloading it and saving it an a binary file causes a crash:
Seems to be a null pointer but I can’t figure out what’s happening.

If I take out the line:
from the xml file then it no longer crashes when saving a binary. Also, weirdly the object when loaded still behaves like a kinematic despite removing the flag (might be related to my code though)

link to the xml file: