DSOD -pytorch problem in evaluation

[hossamems]

Dear Q. Chang
I trained dsod-pytorch on this training data voc_2012 in
http://host.robots.ox.ac.uk/pascal/VOC/voc2012/VOCtrainval_11-May-2012.tar
code and i got this result

and i finished 100 full epoch the evaluation unfortunately got many "Nan"'s as shown in here

of course i got the testing data from http://host.robots.ox.ac.uk:8080/eval/downloads/VOC2012test.tar
kindly help em what is wrong and how to solve it