Error(s) in re-building vignettes:
--- re-building 'FixedParameters.Rmd' using rmarkdown
--- finished re-building 'FixedParameters.Rmd'

--- re-building 'nlsr-derivs.Rmd' using rmarkdown
Loading required package: Ryacas

Attaching package: 'Ryacas'

The following object is masked from 'package:stats':

    integrate

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

    %*%, diag, diag<-, lower.tri, upper.tri

! Undefined control sequence.
l.187 \n
          invalid expression in `FindSubexprs'\n'' \#\# - attr(\emph{, 

Error: processing vignette 'nlsr-derivs.Rmd' failed with diagnostics:
LaTeX failed to compile C:/r_packages/pkgcheck/CRAN/nlsr/nlsr.Rcheck/vign_test/nlsr/vignettes/nlsr-derivs.tex. See https://yihui.org/tinytex/r/#debugging for debugging tips. See nlsr-derivs.log for more info.
--- failed re-building 'nlsr-derivs.Rmd'

--- re-building 'nlsr-devdoc.Rmd' using rmarkdown
! Undefined control sequence.
l.359 \textless- jj jj \}cat(``try nlfb\n
                                         '')\#\# try nlfb st \textless- 

Error: processing vignette 'nlsr-devdoc.Rmd' failed with diagnostics:
LaTeX failed to compile C:/r_packages/pkgcheck/CRAN/nlsr/nlsr.Rcheck/vign_test/nlsr/vignettes/nlsr-devdoc.tex. See https://yihui.org/tinytex/r/#debugging for debugging tips. See nlsr-devdoc.log for more info.
--- failed re-building 'nlsr-devdoc.Rmd'

--- re-building 'nlsr-nls-nlsLM.Rmd' using rmarkdown
[WARNING] Citeproc: citation examples not found
[WARNING] Citeproc: citation export not found
[WARNING] Citeproc: citation param not found
[WARNING] Citeproc: citation references not found
[WARNING] Citeproc: citation return not found
! Undefined control sequence.
l.416 \} else \{ cat(sobj,'' does not exist\n
                                             ``) \} \# return(NULL) \}start1 

Error: processing vignette 'nlsr-nls-nlsLM.Rmd' failed with diagnostics:
LaTeX failed to compile C:/r_packages/pkgcheck/CRAN/nlsr/nlsr.Rcheck/vign_test/nlsr/vignettes/nlsr-nls-nlsLM.tex. See https://yihui.org/tinytex/r/#debugging for debugging tips. See nlsr-nls-nlsLM.log for more info.
--- failed re-building 'nlsr-nls-nlsLM.Rmd'

SUMMARY: processing the following files failed:
  'nlsr-derivs.Rmd' 'nlsr-devdoc.Rmd' 'nlsr-nls-nlsLM.Rmd'

Error: Vignette re-building failed.
Execution halted