the predicted image is all black using trained model on VOC

[czzerone]

Hello, I used the following command to train the segmentation model on PASCAL VOC 2012
/home/server6/Segmentation/Resnet/ademxapp-master/venv/bin/python2.7 issegm/voc.py --gpu 0,1 --split train --data-root /home/server6/xly/SSENet_self_supervised --output output --model voc_rna-a1_cls21 --batch-image 4 --crop-size 500 --origin-size 2048 --scale-rate-range 0.7,1.3 --weights /home/server6/xly/SSENet_self_supervised/weights/ilsvrc-cls_rna-a1_cls1000_ep-0001.params --lr-type fixed --base-lr 0.0016 --to-epoch 140 --kvstore local --prefetch-threads 8 --prefetcher process --backward-do-mirror

but when I used the trained model to predict the image in val set, the result is all black. Can you give me some advice on it? thanks~