pandoc document conversion failed with error 1 after update to R version 3.4.2

Question

After updating to R Version 3.4.2 my flexdashboard documents with shiny do not work anymore.

Even if I try to run a copy of that example https://jjallaire.shinyapps.io/shiny-biclust/
I got that

'Error: pandoc document conversion failed with error 1'

.

Until now I did not find an answer to that error during my websearch. I also updated all packages.

My sessionInfo:

R version 3.4.2 (2017-09-28)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

Matrix products: default

locale:
[1] LC_COLLATE=German_Austria.1252  LC_CTYPE=German_Austria.1252    LC_MONETARY=German_Austria.1252
[4] LC_NUMERIC=C                    LC_TIME=German_Austria.1252    

attached base packages:
[1] grid      stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] biclust_1.2.0    lattice_0.20-35  colorspace_1.3-2 MASS_7.3-47     

loaded via a namespace (and not attached):
 [1] flexclust_1.3-4   Rcpp_0.12.13      digest_0.6.12     rprojroot_1.2     jsonlite_1.5      backports_1.1.1  
 [7] stats4_3.4.2      magrittr_1.5      evaluate_0.10.1   stringi_1.1.5     rpart_4.1-11      rmarkdown_1.7    
[13] flexdashboard_0.5 tools_3.4.2       stringr_1.2.0     parallel_3.4.2    yaml_2.1.14       compiler_3.4.2   
[19] htmltools_0.3.6   knitr_1.17        modeltools_0.2-21

Has anyone an Idea what I could try to solve that?

EDIT:

Maybe this Info can help to find the reason of the Error:
When trying a copy of the "Diamond Explorer" example https://jjallaire.shinyapps.io/shiny-ggplot2-diamonds/ the result is that:

screenshot of my Diamond Explorer copy - result

and I can see that error Messages in RStudio:

Output created:  
C:/Users/xxx/AppData/Local/Temp/RtmpMdOsLH/file1ce033bb6c82.html
Warnung: Error in sample.int: Objekt 'input' nicht gefunden
Stack trace (innermost first):
120: sample.int
119: sample
118: lapply
117: map
116: [.tbl_df
115: [ [<text>#2]
114: <reactive:dataset> [<text>#2]
103: dataset
102: ggplot [<text>#6]
101: renderPlot [<text>#6]
 91: <reactive:plotObj>
 80: plotObj
 79: origRenderFunc
 78: output$outcca1a5b38b4e8b1a
  3: <Anonymous>
  2: do.call
  1: rmarkdown::run

Answer 1

Finally I found a solution for my problem: After reading that https://github.com/rstudio/rmarkdown/issues/1184
and installing an actual rmarkdown package from github:
devtools::install_github('rstudio/rmarkdown') my flexdashboard documents with shiny works again :-)