So I did some digging, looks like the R CMD SHLIB file mentioned in the above error message is used by R to compile source code in R packages (such as Stan) and to link object files into a specific object. When I follow the path from the error message
C:/PROGRA~1/R/R-40~1.2/bin/x64/R CMD SHLIB file44f8185f33.cpp 2
I do not have a filed named Rcmdshlib. I suspect this is from installation but tried a fresh install of R and the file is still missing. I hope this helps narrow down the issue