title: r shiny data table sometimes does not display
body: <p>I encountered a weird situation that made me confused and searched for a while but seems no same issues as mine with data table package. </p>
  
  <p>I simply used the basic default data table in my shiny app, see example: </p>
  
  <p><strong>Server.R</strong></p>
  
  <pre><code> library(shiny)
   library(DT)
   shinyServer(function(input, output) {
  
   output$expense_table_check&lt;-renderDataTable({
     iris
   })
  })
  </code></pre>
  
  <p><strong>ui.R</strong></p>
  
  <pre><code>library(shiny)
  shinyUI(fluidPage(
  mainPanel(
        navlistPanel(
         tabPanel("DT",h1("DT"),
         dataTableOutput("expense_table_check"))
     )
    )
   ) 
  )
  </code></pre>
  
  <p>Sometimes the above works fine but sometimes not. I tried replacing <code>dataTableOutput("expense_table_check")</code> with 
  <code>dataTableOutput('expense_table_check')</code> and then it works sometimes, but sometime not. </p>
  
  <p>I also tried replacing the output name <code>expense_table_check</code> with <code>expense_table_check2</code>. But still cannot solve the issue. Any suggestion or comment is appreciated. </p>