I love flextable and so I use it in a lot of projects. After setup of a new Laptop where I installed R 4.4.1 and RStudio 2024.04.2 I had to see that the flextable library (0.9.6) produces an error when it is attached in a quarto document (.qmd) but there is no problem when it is attached in a RMarkdown document (.Rmd).
The error occurs immediately after klicking the render button auf a .qmd file and looks like this: