What is the graphics::par(op) in R?

Question

Working with Quanteda in R, and passing DTM to textplot_wordcloud returns the following error

Error in graphics::par(op) : invalid value specified for graphical parameter "pin"

There's one other question but the answer refers to a specific package that forces the issue and so a workaround is given that is unclear to me. What does this refer to and how can I go about debugging this? I've never come across the "pin" before but I'm presuming this is related to positioning on the graphical plane somehow. Just unsure how to alter settings in quanteda textplot_wordcloud? Any guidance appreciated.