RuntimeError: Need all tensors to have same lenght

I am a complete freshman when it comes to neural networks. I need to use them in my thesis as a complement to the Cox model analyses. When creating the network in the same way as shown on the website code, an error occurs:

Error in 'py_call_impl(callable, dots$args, dots$keywords)' command:
  RuntimeError: Need all tensors to have same lenght.

How can I check the lengths of the tensors or change them to make this function work? I have zero knowledge of this and would like to figure it out.

ANSWER: if someone is interested in solving the problem, it turned out that in the data set was a missing data, which before setting up the network had to be simply removed with the function na.omit()