How to make the horizontal scrollbar visible in DT::datatable

I don't think you can (or should) force a scrollbar easily if you don't need one, but the above code works fine for me, it shows a scrollbar when the page initializes. Maybe the problem is with the data or something else.

Here's a minimal example that has a horizontal scrollbar on page load

runApp(shinyApp(  ui = fluidPage(    DT::dataTableOutput("results", width = 300)  ),  server = function(input, output, session) {    output$results <- DT::renderDataTable(      mtcars,      options = list(scrollX = TRUE)    )  }))

Try this:

DT::datatable(sta, options = list(  pageLength=50, scrollX='400px'), filter = 'top')

I would have done this way also:

datasetInput1 <- reactive({      infile <- input$file1      if(is.null(infile))        return(NULL)       else        m <- read.csv(infile$datapath, header = input$header)        return ( DT::datatable(m, extensions = 'Scroller', options = list(deferRender = F, dom = 't',                                                                      columnDefs = list(list(className = 'dt-center',                                                                                             targets = 5)),                                                                     scrollY = 300, scroller = TRUE, scrollX = T,                                                                     pageLength = 5))               )    })