sjplot's xtabs function gives error when trying to produce crosstabulation table

Question

I've downloaded the lastest version of sjplot and sjmisc. They aren't working correctly: I am unable to produce a simple crosstable of two variables:

sjt.xtab (mydataset$gender, mydateset$age)

Error: 'table_values' is not an exported object from 'namespace:sjmisc'

This is regardless of which of my variables I attempt to crosstab. Oddly, if I use sjp.xtab it works fine, though with a warning message:

sjp.xtab (mydataset$gender, mydateset$age)

Warning message:
Deprecated, use tibble::rownames_to_column() instead.

Does anyone have any idea what I have to do to fix this?