训练faster rcnn的时候遇到的问题

speed: 1.352s / iter
Traceback (most recent call last):
  File "./tools/train_net.py", line 112, in <module>
    max_iters=args.max_iters)
  File "/home/zhangning/faster-rcnn/tools/../lib/fast_rcnn/train.py", line 160, in train_net
    model_paths = sw.train_model(max_iters)
  File "/home/zhangning/faster-rcnn/tools/../lib/fast_rcnn/train.py", line 108, in train_model
    model_paths.append(self.snapshot())
  File "/home/zhangning/faster-rcnn/tools/../lib/fast_rcnn/train.py", line 73, in snapshot
    self.bbox_stds[:, np.newaxis])
ValueError: operands could not be broadcast together with shapes (84,4096) (12,1)