I compiled a 32-bit version of Panda3D and got the same assertion, which did indeed turn out to be caused by an attached gamepad. So assuming you are getting the same issue, I’ve just checked in a fix:
The automatic build server is not currently functioning well, so here is a wheel you could try:
http://rdb.name/panda3d-1.11.0-cp37-cp37m-win32.whl
However, I recommend installing the 64-bit version of Python and Panda3D instead if at all possible.