title: R's shiny app goes grey when deployed, works fine locally
body: <p>I've created two shiny apps running on shinyapps.io and both have the same problem that I haven't been able to solve: after a few mins into an active instance of the web app (a few mins after navigating to the web app in a browser), the screen goes grey. This problem happens when I navigate to the website of the deployed app, but when I run the app from RStudio, the browser window that pops up doesn't turn grey and behaves as it should.</p>
  
  <p>Many people have posted on google groups, stackoverflow, and github about this problem. I've tried all of the relevant proposed solutions for how to fix it and none of them have worked for me:</p>
  
  <ul>
  <li><p>Screen may be turning grey because of an error in the ui or server code I wrote. The proposed solution is to run </p>
  
  <p>shinyapps::showLogs() </p></li>
  </ul>
  
  <p>according to advice found <a href="https://github.com/rstudio/shinyapps/issues/133">here</a>. But I've done this, and it doesn't output any error messages (see below).</p>
  
  <ul>
  <li>According to the rstudio shiny help page titled 'Scaling and Performance Tuning with shinyapps.io' under the heading 'Troubleshooting' (sorry, stackoverflow won't let me post more than 1 link), the cause of problem might be that my app is using too much memory and the shinyapps.io server kills the instance. I've done the two things they suggest, increasing the size of the application instance and decreasing the number of workers per application instance. Neither have fixed the issue. I have a feeling this isn't the problem because one of my apps is extremely simple and the calculations it makes are done within a second or two when run locally. I've also checked out the memory usage of the apps on the shiny dashboard and the usage is no where near the memory limit.</li>
  </ul>
  
  <p>Any suggestions of what might be going wrong or what to change are greatly appreciated!</p>
  
  <p>Output from <code>shinyapps::showLogs()</code> :</p>
  
  <pre><code>2016-01-09T02:42:48.551801+00:00 shinyapps[67824]: Starting R with process ID: '26'
  2016-01-09T02:42:48.556484+00:00 shinyapps[67824]: 
  2016-01-09T02:42:48.556486+00:00 shinyapps[67824]: Listening on http://0.0.0.0:53774
  2016-01-09T02:43:40.334353+00:00 shinyapps[67824]: R version: 3.1.2
  2016-01-09T02:43:40.334428+00:00 shinyapps[67824]: shiny version: 0.11.1
  2016-01-09T02:43:40.334430+00:00 shinyapps[67824]: rmarkdown version: NA
  2016-01-09T02:43:40.334431+00:00 shinyapps[67824]: knitr version: NA
  2016-01-09T02:43:40.334442+00:00 shinyapps[67824]: jsonlite version: 0.9.14
  2016-01-09T02:43:40.334443+00:00 shinyapps[67824]: RJSONIO version: 1.3.0
  2016-01-09T02:43:40.334444+00:00 shinyapps[67824]: htmltools version: 0.2.6
  2016-01-09T02:43:40.582614+00:00 shinyapps[67824]: Using jsonlite for JSON processing
  2016-01-09T02:43:40.586355+00:00 shinyapps[67824]: 
  2016-01-09T02:43:40.586357+00:00 shinyapps[67824]: Starting R with process ID: '36'
  2016-01-09T02:43:40.590767+00:00 shinyapps[67824]: 
  2016-01-09T02:43:40.590769+00:00 shinyapps[67824]: Listening on http://0.0.0.0:33335
  2016-01-09T03:11:48.268226+00:00 shinyapps[67824]: R version: 3.1.2
  2016-01-09T03:11:48.268317+00:00 shinyapps[67824]: shiny version: 0.11.1
  2016-01-09T03:11:48.268318+00:00 shinyapps[67824]: rmarkdown version: NA
  2016-01-09T03:11:48.268335+00:00 shinyapps[67824]: knitr version: NA
  2016-01-09T03:11:48.268336+00:00 shinyapps[67824]: jsonlite version: 0.9.14
  2016-01-09T03:11:48.268337+00:00 shinyapps[67824]: RJSONIO version: 1.3.0
  2016-01-09T03:11:48.268338+00:00 shinyapps[67824]: htmltools version: 0.2.6
  2016-01-09T03:11:48.515347+00:00 shinyapps[67824]: Using jsonlite for JSON processing
  2016-01-09T03:11:48.519056+00:00 shinyapps[67824]: 
  2016-01-09T03:11:48.519058+00:00 shinyapps[67824]: Starting R with process ID: '46'
  2016-01-09T03:11:48.523399+00:00 shinyapps[67824]: 
  2016-01-09T03:11:48.523401+00:00 shinyapps[67824]: Listening on http://0.0.0.0:37152
  2016-01-16T01:13:14.357697+00:00 shinyapps[67824]: R version: 3.1.2
  2016-01-16T01:13:14.357788+00:00 shinyapps[67824]: shiny version: 0.11.1
  2016-01-16T01:13:14.357790+00:00 shinyapps[67824]: rmarkdown version: NA
  2016-01-16T01:13:14.357791+00:00 shinyapps[67824]: knitr version: NA
  2016-01-16T01:13:14.357792+00:00 shinyapps[67824]: jsonlite version: 0.9.14
  2016-01-16T01:13:14.357809+00:00 shinyapps[67824]: RJSONIO version: 1.3.0
  2016-01-16T01:13:14.357811+00:00 shinyapps[67824]: htmltools version: 0.2.6
  2016-01-16T01:13:14.795787+00:00 shinyapps[67824]: Using jsonlite for JSON processing
  2016-01-16T01:13:14.799494+00:00 shinyapps[67824]: 
  2016-01-16T01:13:14.799495+00:00 shinyapps[67824]: Starting R with process ID: '11'
  2016-01-16T01:13:14.806392+00:00 shinyapps[67824]: 
  2016-01-16T01:13:14.806394+00:00 shinyapps[67824]: Listening on http://0.0.0.0:49762
  2016-01-17T06:48:58.595979+00:00 shinyapps[67824]: R version: 3.1.2
  2016-01-17T06:48:58.596062+00:00 shinyapps[67824]: shiny version: 0.11.1
  2016-01-17T06:48:58.596064+00:00 shinyapps[67824]: rmarkdown version: NA
  2016-01-17T06:48:58.596065+00:00 shinyapps[67824]: knitr version: NA
  2016-01-17T06:48:58.596077+00:00 shinyapps[67824]: jsonlite version: 0.9.14
  2016-01-17T06:48:58.596078+00:00 shinyapps[67824]: RJSONIO version: 1.3.0
  2016-01-17T06:48:58.596079+00:00 shinyapps[67824]: htmltools version: 0.2.6
  2016-01-17T06:48:58.999625+00:00 shinyapps[67824]: Using jsonlite for JSON processing
  2016-01-17T06:48:59.003284+00:00 shinyapps[67824]: 
  2016-01-17T06:48:59.003287+00:00 shinyapps[67824]: Starting R with process ID: '11'
  2016-01-17T06:48:59.010065+00:00 shinyapps[67824]: 
  2016-01-17T06:48:59.010067+00:00 shinyapps[67824]: Listening on http://0.0.0.0:37097
  </code></pre>
  
  <p>Here's an example of one of the problematic shiny apps: <a href="https://rosemarie-p-b-scott.shinyapps.io/OM_2266/">https://rosemarie-p-b-scott.shinyapps.io/OM_2266/</a></p>