Fix RuntimeError

✅ Solution

RuntimeError in PyTorch often arises from operations not supported on the given tensor type or device, or from incorrect gradient flow in custom autograd functions. Ensure all operations are compatible with the tensor's device (CPU/GPU) and data type (e.g., sparse tensors may have limited operation support). If implementing custom autograd functions, double-check the backward pass for correct gradient calculations and handling of non-differentiable operations, potentially using 'torch.autograd.gradcheck' for verification.