NoneType' object has no attribute 'MXNDArrayFree'

mxnet 1.5.1 . compiled from source

I have below error any idea :

File “/home/nvidia/Projects/BC/mxnet/python/mxnet/_ctypes/”, line 51, in del
AttributeError: ‘NoneType’ object has no attribute ‘MXNDArrayFree’
Exception ignored in: <object repr() failed>
Traceback (most recent call last):

Can you share a small example, so that I can try to reproduce the error?