title: ShinyApp Error During Deployment: Execution Halted
body: <p>I am having trouble during deployment to shinyapps.io of an application that is working locally. The application uses <strong>shiny</strong> and <strong>shinydashboard</strong>. I am able to run the app in RStudio, but when I click publish it halts execution with no discernible error reported. The error message I receive is:</p>
  
  <pre><code>Error: Unhandled Exception: Child Task 71390052 error: Unhandled Exception: 
  Execution halted
  </code></pre>
  
  <p>Also, when I run <code>shinyapps::showLogs()</code> nothing is returned.</p>
  
  <p>I have checked to see that all required packages are updated and to the best of my knowledge they are. A call to <code>sessionInfo()</code> gives:</p>
  
  <pre><code>R version 3.1.3 (2015-03-09)
  Platform: x86_64-w64-mingw32/x64 (64-bit)
  Running under: Windows 8 x64 (build 9200)
  
  locale:
  [1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252   
  [3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C                          
  [5] LC_TIME=English_United States.1252    
  
  attached base packages:
  [1] grid      stats     graphics  grDevices utils     datasets  methods   base     
  
  other attached packages:
  [1] gtable_0.1.2         gridExtra_2.0.0      ggplot2_1.0.1        dplyr_0.4.2         
  [5] jsonlite_0.9.16      DT_0.1.32            shinydashboard_0.5.0 shiny_0.12.2 
  </code></pre>
  
  <p>I know this isn't a lot to go on, but since the application works fine locally and there are no error messages, I'm not sure what code would be useful. I've looked at any other SO questions I could find on shiny deployment errors, but they all have a useful error message.</p>
  
  <p>Any debugging suggestions, help, or other ideas are greatly appreciated.</p>