I am using
"11.2.0 for Mac OS X x86 (64-bit) (September 11, 2017)"
and I am trying to install the RGTC package, which can be found here.
Then following the answer given by Szabolcs here How to Install packages
after I unzip the folder, I opened the EDCRGTCcode.m and then did the following
Choose File -> Install... Choose Type -> Package, Source -> (the open notebook), Install Name -> (i used the exact same name that the notebook has)
Then, I tried to load the package by evaluating
but I get the following error
During evaluation of In:= Get::noopen: Cannot open EDCRGTCcode.m`. $Failed