Thanks for the code.
Unfortunately, there are some unknown functions and classes, so that I cannot run the code on my machine.
Could you create a dummy code like this:
data = torch.randn(YOUR_SIZE)
model = CRNN(YOUR_ARGS)
output = model(data) # error here?

This would make it possible to debug your model architecture.
Also, it seems the error is thrown during the validation.
If so, could you check you are passing the right input shapes as you used during training?