raise ValueError("Segmentation map contained invalid class values")

[ThinkPig826]

when i test the mode: python validate.py --model_path weights/hardnet70_cityscapes_model.pkl

raise self.exc_type(msg)

ValueError: Caught ValueError in DataLoader worker process 0.
Original Traceback (most recent call last):
File "/usr/local/lib/python3.6/dist-packages/torch/utils/data/_utils/worker.py", line 185, in _worker_loop
data = fetcher.fetch(index)
File "/usr/local/lib/python3.6/dist-packages/torch/utils/data/_utils/fetch.py", line 44, in fetch
data = [self.dataset[idx] for idx in possibly_batched_index]
File "/usr/local/lib/python3.6/dist-packages/torch/utils/data/_utils/fetch.py", line 44, in
data = [self.dataset[idx] for idx in possibly_batched_index]
File "/home/yijiahe/AI/FCHarDNet/ptsemseg/loader/cityscapes_loader.py", line 170, in getitem
img, lbl = self.transform(img, lbl)
File "/home/yijiahe/AI/FCHarDNet/ptsemseg/loader/cityscapes_loader.py", line 209, in transform
raise ValueError("Segmentation map contained invalid class values")
ValueError: Segmentation map contained invalid class values