Unused argument error might appear with any function (for example, dplyr), and the primal cause is a misunderstanding. If function appears in multiple active libraries, then you have to make sure which of them are you using. If you are not using that you think you are using, then it is no surprise that error comes.
For dplyr, this unused argument error might happen with the MASS package when using function “select”. You can check that out by writing the function in the console. When dplyr and MASS are loaded, then “select” is used with MASS.
One of the best solutions to this problem is using the name of the package (namespace) with necessary function like this – dplyr::select.
Check out this other post where you can if you want custom function assign to some package namespace.