whenever make Cadabra do lengthy calculations, I always get error on output

Question

I get the following error

{\color{red}{\begin{verbatim}RuntimeError: Free indices in different terms in a sum do not match.

At:

(4): \end{verbatim}}}

and cadabra quits on me. Always. Any solutions to this problem?

Answer 1

You'll have to make this a bit more specific. Can you email me (info@cadabra.science) a notebook that fails in this way (preferably as short as possible)?