Error(s) in re-building vignettes:
  ...
--- re-building ‘DIF_vignette.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.

Attaching package: 'dplyr'

The following objects are masked from 'package:stats':

    filter, lag

The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

no column `person_id` provided, automatically generating unique person id's
--- finished re-building ‘DIF_vignette.Rmd’

--- re-building ‘Dexter.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.

Attaching package: 'dplyr'

The following objects are masked from 'package:stats':

    filter, lag

The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

--- finished re-building ‘Dexter.Rmd’

--- re-building ‘Equating.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
no column `person_id` provided, automatically generating unique person id's
no column `person_id` provided, automatically generating unique person id's
no column `person_id` provided, automatically generating unique person id's
Quitting from lines 236-243 (Equating.Rmd) 
Error: processing vignette 'Equating.Rmd' failed with diagnostics:
Error in solve.default(H * scale, sufI - EsufI) : 
  system is computationally singular: reciprocal condition number = 1.05711e-17

--- failed re-building ‘Equating.Rmd’

--- re-building ‘Plausible_Values.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘Plausible_Values.Rmd’

--- re-building ‘Profile-plots.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
no column `person_id` provided, automatically generating unique person id's
--- finished re-building ‘Profile-plots.Rmd’

--- re-building ‘Test_Individual_differences.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
no column `person_id` provided, automatically generating unique person id's
--- finished re-building ‘Test_Individual_differences.Rmd’

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

Error: Vignette re-building failed.
Execution halted