* checking for file ‘./DESCRIPTION’ ... OK
* preparing ‘mkin’:
* checking DESCRIPTION meta-information ... OK
* installing the package to build vignettes
* creating vignettes ... ERROR
--- re-building ‘FOCUS_D.rmd’ using rmarkdown
--- finished re-building ‘FOCUS_D.rmd’

--- re-building ‘FOCUS_L.rmd’ using rmarkdown
Quitting from lines 80-83 (FOCUS_L.rmd) 
Error: processing vignette 'FOCUS_L.rmd' failed with diagnostics:
argument 1 (type 'list') cannot be handled by 'cat'
--- failed re-building ‘FOCUS_L.rmd’

--- re-building ‘mkin.rmd’ using rmarkdown
--- finished re-building ‘mkin.rmd’

--- re-building ‘twa.rmd’ using rmarkdown
--- finished re-building ‘twa.rmd’

SUMMARY: processing the following file failed:
  ‘FOCUS_L.rmd’

Error: Vignette re-building failed.
Execution halted