Sparse matrix methods fail when run with Rscript

[kbseah]

Functions manipulating dgTMatrix work when run in interactive R session but fail with Rscript. Error message produced:

Error in validObject(r) : 
  invalid class “dgTMatrix” object: Not a valid 'Mnumeric' class object
Calls: msimat -> <Anonymous> -> validObject
Execution halted

This appears to be an issue with Rscript not loading methods automatically. The workaround is to library(methods) when running as a script. Also affects Jupyter Notebook sessions. See StackOverflow