I have a number of notebooks written for whatever the current version was of Mathematica in 2019 (not 1919 as I had earlier) and using the `ccgrg` package for general relativity. They now no longer work. There is no error, but the key functions such as `tRicciR[a,b]` that should give something like

 tRicciR[1, 1]

 (* (2 [Alpha] [Lambda] + x^2 [Beta]^2 [Lambda]^2 + y^2 [Beta]^2 [Lambda]^2 + 4 z^2 [Beta]^2 [Lambda]^2 - *********** *)

but just return `tRicciR[a,b]` rather than evaluating the function. Is this a known problem? And If there is no way to get `ccgrg` to run in 12, is there a way to resurrect the 2019 version of Mathematica? I've lost a lot of work if it is a dead package

[![enter image description here][1]][1]


 [1]: https://i.sstatic.net/uieAB.png