assert self.weight_bias is not None AssertionError

(neon) :~/Documents/ModelZoo/TransferLearning/PASCALVOC$ ./transfer_learning.py -e10 -r13 -b mkl --save_path model.prm --serialize 1 --history 20
2018-04-13 07:06:32,066 - neon.optimizers.optimizer - WARNING - This functionality will be removed from Schedule in the future. Please use the StepSchedule class instead.
2018-04-13 07:06:32,066 - neon.backends - WARNING - deterministic_update and deterministic args are deprecated in favor of specifying random seed
prepare PASCAL VOC trainval from year 2007: add flipped image False and overlap threshold 0.5
Backend batchsize is changed to be 64 from PASCAL_VOC dataset
ROI dataset loaded from file /home/user/nervana/data/VOCdevkit/VOC2007/train_voc_2007_trainval_flip_False_ovlp_0.5_size_1000_600_v2.pkl
trainval Datatset: # images:5000
Loading the Alexnet pre-trained with ImageNet I1K from: /home/user/nervana/data/alexnet.p
Loading weights for:Convolution_bias_0 [src: Convolution_0]
Traceback (most recent call last):
File "./transfer_learning.py", line 640, in
main()
File "./transfer_learning.py", line 75, in main
load_imagenet_weights(model, args.data_dir)
File "./transfer_learning.py", line 207, in load_imagenet_weights
layer.load_weights(ps, load_states=True)
File "/home/user/anaconda2/envs/neon/lib/python3.6/site-packages/nervananeon-2.6.0-py3.6.egg/neon/layers/layer.py", line 249, in load_weights
self.set_params(pdict)
File "/home/user/anaconda2/envs/neon/lib/python3.6/site-packages/nervananeon-2.6.0-py3.6.egg/neon/layers/layer.py", line 1028, in set_params
assert self.weight_bias is not None
AssertionError

Please guide me, Thanks.