Error(s) in re-building vignettes:
  ...
--- re-building ‘bs4Dash.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) not available. Falling back to R Markdown v1.
Error: processing vignette 'bs4Dash.Rmd' failed with diagnostics:
there is no package called 'stringr'
--- failed re-building ‘bs4Dash.Rmd’

--- re-building ‘css-preloader.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) not available. Falling back to R Markdown v1.
Error: processing vignette 'css-preloader.Rmd' failed with diagnostics:
there is no package called 'stringr'
--- failed re-building ‘css-preloader.Rmd’

--- re-building ‘extra-elements.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) not available. Falling back to R Markdown v1.
Error: processing vignette 'extra-elements.Rmd' failed with diagnostics:
there is no package called 'stringr'
--- failed re-building ‘extra-elements.Rmd’

--- re-building ‘improved-boxes.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) not available. Falling back to R Markdown v1.
Error: processing vignette 'improved-boxes.Rmd' failed with diagnostics:
there is no package called 'stringr'
--- failed re-building ‘improved-boxes.Rmd’

--- re-building ‘more-skins.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) not available. Falling back to R Markdown v1.
Error: processing vignette 'more-skins.Rmd' failed with diagnostics:
there is no package called 'stringr'
--- failed re-building ‘more-skins.Rmd’

--- re-building ‘step-by-step.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) not available. Falling back to R Markdown v1.
Error: processing vignette 'step-by-step.Rmd' failed with diagnostics:
there is no package called 'stringr'
--- failed re-building ‘step-by-step.Rmd’

SUMMARY: processing the following files failed:
  ‘bs4Dash.Rmd’ ‘css-preloader.Rmd’ ‘extra-elements.Rmd’
  ‘improved-boxes.Rmd’ ‘more-skins.Rmd’ ‘step-by-step.Rmd’

Error: Vignette re-building failed.
Execution halted