If Google leads you here, you probably have assigned a character value to a knitr chunk option such as fig.width or fig.height that only accepts numeric values, and your are trying to render that R Markdown or Quarto document.
For example, it is easy to make this mistake:
{r, fig.width="100%"} plot(1:10) where you probably meant:
{r, fig.width=6, out.width="100%"} plot(1:10) That’s all! I hope this …