Error(s) in re-building vignettes:
  ...
--- re-building ‘Chapter10Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter10Solutions.Rmd’

--- re-building ‘Chapter11Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter11Solutions.Rmd’

--- re-building ‘Chapter12Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter12Solutions.Rmd’

--- re-building ‘Chapter13Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter13Solutions.Rmd’

--- re-building ‘Chapter14Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter14Solutions.Rmd’

--- re-building ‘Chapter15Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter15Solutions.Rmd’

--- re-building ‘Chapter16Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter16Solutions.Rmd’

--- re-building ‘Chapter17Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter17Solutions.Rmd’

--- re-building ‘Chapter1Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter1Solutions.Rmd’

--- re-building ‘Chapter2Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter2Solutions.Rmd’

--- re-building ‘Chapter3Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter3Solutions.Rmd’

--- re-building ‘Chapter4Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter4Solutions.Rmd’

--- re-building ‘Chapter5Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter5Solutions.Rmd’

--- re-building ‘Chapter6Solutions.Rmd’ using rmarkdown

Quitting from lines 45-50 [box6.1] (Chapter6Solutions.Rmd)
Error: processing vignette 'Chapter6Solutions.Rmd' failed with diagnostics:
there is no package called 'lme4'
--- failed re-building ‘Chapter6Solutions.Rmd’

--- re-building ‘Chapter7Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter7Solutions.Rmd’

--- re-building ‘Chapter8Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter8Solutions.Rmd’

--- re-building ‘Chapter9Solutions.Rmd’ using rmarkdown
--- finished re-building ‘Chapter9Solutions.Rmd’

--- re-building ‘ecostats.Rmd’ using rmarkdown
--- finished re-building ‘ecostats.Rmd’

SUMMARY: processing the following file failed:
  ‘Chapter6Solutions.Rmd’

Error: Vignette re-building failed.
Execution halted