Are there any symmetry finding packages (for differential equations) that work with Mathematica 11.1? I've tried MathLie but from looking at the documentation it had instructions for Windows 95... I attempted installation of the MathLie package on Windows 10 by placing it in the AddOns/Packages folder and the import (Needs[*]) worked but none of the commands did. After inspecting the files further it said it had support for v3-4 of Mathematica.
Then, I looked at SYM but had a similar problem. Looking at the site where it's download is listed it only seems to go up to Mathematica 8.x.