R Studio won't run it at all

[jennygel13]

I'm not sure if this is the right place but when I install artool it says the namespace doesn't exist. Its not the code since it runs fine on classmate's computers with same Rstudio versions and same exact laptop model. ARTool installs in the system library (bottom right section with no tick), but when I try to load the library the error in the picture appears. No one knows how to fix it and I can't download this 'Matrix' package. Please help.