I have a number of notebooks written for whatever the current version was of Mathematica in 1990 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
In[243]:= tRicciR[1, 1]
Out[243]= (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 1990 version of Mathematica? I've lost a lot of work if it is a dead package.
