Dataloader Error: AttributeError: 'NoneType' object has no attribute 'Pool'

Hi Team,

I get the error “AttributeError: ‘NoneType’ object has no attribute ‘Pool’” after my training loop completes and before exiting the program in SageMaker.
My mxnet version is:
(mxnet_p36) sh-4.2$ pip list|grep mxnet
aws-mxnet-cu101mkl 1.6.0
keras-mxnet 2.2.4.2
mxnet-model-server 1.0.8

The training finishes successfully but the program fails to exit.
Here is the detailed error:

Exception ignored in: <bound method DataLoader.del of <mxnet.gluon.data.dataloader.DataLoader object at 0x7f45a99f9208>>
Traceback (most recent call last):
File “/home/ec2-user/anaconda3/envs/mxnet_p36/lib/python3.6/site-packages/mxnet/gluon/data/dataloader.py”, line 678, in del
AttributeError: ‘NoneType’ object has no attribute ‘Pool’

Any thoughts on how I can debug this?
Thanks!