Unable to read an SBML file in SBMLR

Question

I'm trying to read a SBML file (Test.xml) using the R package SBMLR. Below is the code I executed.

library(SBMLR)
file <- system.file("models","Test.xml",package = "SBMLR")
doc <- readSBML(file)

When I execute the 3rd line I get an error message saying:

Error in xmlEventParse(filename, handlers = sbmlHandler(), ignoreBlanks = TRUE) : File does not exist

I have tried to read the file using rsbml library as well.. But still I'm getting an error saying

Error: File unreadable.

I'm following this guide at the moment. Any help regarding the issue is highly appreciated!