I tried a 'flexdashboard' themed with 'bslib' (in RStudio: New file -> Rmarkdown -> From template -> flexdashboard themed with bslib). I'm on Windows. When I knit the file (e.g. the default one), the compilation reaches 100% but then an error occurs:
Error in ie_get_proxy_for_url(test_url) :
ERROR_WINHTTP_UNABLE_TO_DOWNLOAD_SCRIPT
Calls : <Anonymous> ... download_file -> <Anonymous> -> ie_get_proxy_for_url