This error is raised, if you try to pass a Size object to as an argument to the layer creation:
x = torch.randn(10, 10)
nn.Linear(x.size(), 10)
> TypeError: new(): argument 'size' must be tuple of ints, but found element of type torch.Size at pos 2

Based on your previous code snippet, input_shape should be defined as input_shape = 256, so I assume you might have changed the code in the meantime.
PS: Please don’t post screenshots, but paste the code directly and wrap it into three backticks ```.