This might be discussed before. But, I cannot find the solution for my specific trouble.
I was trying to run a shiny app on EC2, but failed to render plots due to the failure to start a PNG device obviously. My R version is 3.5.1, Ubuntu version is 16.04. The error msg is like:
Warning in pngfun(filename = filename, width = width, height = height, res = res, : unable to open connection to X11 display '' Warning: Error in .External2: unable to start device PNG 123: pngfun 122: startPNG 121: drawPlot 107: <reactive:plotObj> 91: drawReactive 78: origRenderFunc 77: output$umi_cell_ranking 1: runApp
capabilities() result is as below:
jpeg png tiff tcltk X11 aqua TRUE TRUE FALSE FALSE TRUE FALSE http/ftp sockets libxml fifo cledit iconv TRUE TRUE TRUE TRUE TRUE TRUE NLS profmem cairo ICU long.double libcurl TRUE FALSE FALSE TRUE TRUE TRUE
I assume I installed necessary libraries as guided by online trouble shooting, but not sure complete. Anybody met this before and got a solution?