Quote - > Quote - Also your paths are different than mine.

Matmatic runtime/python/matmatic

and the txt file and compile is runtime/library/material/matmatic demo

respectively

I'm not following what you mean with respect to paths... I'm running version Poser 7 of Matmatic. In the error, there is a reference to a file in Poser 6. I do not have Poser 6 installed, so that path is invalid - indeed, that statement is invalid for my version of Poser. For the Poser 7 version, the right place for the Matmatic files is :runtime:Python:Matmatic... or so I thought. I might be mistaken.

Yes you are correct and your text file goes in the 2nd path as I satated.

Don