Getting below runtime error when i try to validate the Model

[sunilbage]

Traceback (most recent call last):
File "E:\Softwares\AI_Tools\Image_Quality_Assesment\DISTS\DISTS_pytorch\DISTS_pt.py", line 139, in
score = model(ref, dist)
File "D:\ProgramData\Anaconda3\envs\DISTS\lib\site-packages\torch\nn\modules\module.py", line 1130, in _call_impl
return forward_call(*input, **kwargs)
File "E:\Softwares\AI_Tools\Image_Quality_Assesment\DISTS\DISTS_pytorch\DISTS_pt.py", line 106, in forward
xy_cov = (feats0[k]feats1[k]).mean([2,3],keepdim=True) - x_meany_mean
RuntimeError: The size of tensor a (455) must match the size of tensor b (451) at non-singleton dimension 3