Q: pandoc document conversion failed with error 2 when I knit HTML in R studio, I get this:

"C:/Users/Susan/ANACON~1/Scripts/pandoc" +RTS -K512m -RTS lesson3_student.utf8.md --to html --from markdown+autolink_bare_uris+ascii_identifiers+tex_math_single_backslash --output lesson3_student.html --smart --email-obfuscation none --self-contained --standalone --section-divs --template "C:\Users\Susan\Documents\R\win-library\3.3\rmarkdown\rmd\h\default.html" --no-highlight --variable highlightjs=1 --variable "theme:bootstrap" --include-in-header "C:\Users\Susan\AppData\Local\Temp\RtmpaUaaRx\rmarkdown-str3cf45da21737.html" --mathjax --variable "mathjax-url:https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML" 
  output file: lesson3_student.knit.md
unrecognized option `--smart'
  Try pandoc.exe --help for more information.
  Error: pandoc document conversion failed with error 2
  In addition: Warning message:
  running command '"C:/Users/Susan/ANACON~1/Scripts/pandoc" +RTS -K512m -RTS lesson3_student.utf8.md --to html --from markdown+autolink_bare_uris+ascii_identifiers+tex_math_single_backslash --output lesson3_student.html --smart --email-obfuscation none --self-contained --standalone --section-divs --template "C:\Users\Susan\Documents\R\win-library\3.3\rmarkdown\rmd\h\default.html" --no-highlight --variable highlightjs=1 --variable "theme:bootstrap" --include-in-header "C:\Users\Susan\AppData\Local\Temp\RtmpaUaaRx\rmarkdown-str3cf45da21737.html" --mathjax --variable "mathjax-url:https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"' had status 2 
  Execution halted

Can someone give me an idea what went wrong and how to fix it?
Thank you

A: Today I had the same problem.
I fixed it by setting the smart option to false, as described here.
   output:
     html_document: 
       smart: false

It seems that --smart is no longer supported in the newest pandoc version (1.19.2.1), even though it should be should be; see discusion on the RStudio forum
