Shiny app works locally, but failed to start when published to shinyapps.io, logs look normal without errors

[elsiehung]

I have been trying to publish a shiny app for multiple times. It works fine locally, but when publishing to shinyapps.io it keeps showing the "An Error Has Occurred. The Application Failed to Start." However the logs does not display any errors or exit code.

My code below:

#prepare packages
library(shiny)
library(rsconnect)
library(ggplot2)
library(dplyr)
library(readxl)
library(tidyr)
library(lubridate)


#prepare data
df <- read_excel("Data/ERCOT Generation by Fuel data_Jan2009 to Mar2022.xlsx")
df_datetime <- df %>%
  mutate(timestamp = substring(DateTime,1,5)) %>%
  mutate(Date = as.Date(Date)) %>%
  gather(key = "Fuel", value = "Gen_MWh", 
         Nuclear, Coal, Hydro, `All Other`, Gas, `Gas CC`, Wind, Solar) %>%
  mutate(time_only = hm(timestamp)) %>%
  mutate(time_sameday = ymd_hm(paste(Sys.Date(),hour(time_only),minute(time_only))))


# Define UI for application that draws a histogram
ui <- fluidPage(
  
  # Application title
  titlePanel("ERCOT Generation by Fuel"),
  
  #plot
  plotOutput("Plot2", height = 700),
  
  hr(),
  # Sidebar with a slider input for date
  fluidRow(
    column(12,
           wellPanel(
             dateInput("Date_calendar",
                       label = "Select a Date:",
                       value = as.Date("2022-01-01"),
                       min = as.Date("2009-01-01","%Y-%m-%d"),
                       max = as.Date("2022-03-31","%Y-%m-%d")
             ),
             uiOutput("slider")
             
           )
    )
  )
)

# Define server logic required to draw a histogram
server <- function(input, output) {
  
  output$Plot2 <- renderPlot({
    df_datetime %>%
      filter(Date %in% input$Date) %>%
      ggplot(aes(x = time_sameday, y = Gen_MWh, fill = factor(Fuel, levels = c("Solar", "Wind", "Gas", "Gas CC", "All Other", "Hydro", "Coal", "Nuclear") ) )) + 
      geom_bar(position = "stack", stat='identity') +
      scale_fill_manual(values = c("orange", "purple", "red", "pink1", "brown", "blue", "gray50", "gold"))+
      scale_x_datetime(date_labels = "%H:%M")+
      ylim(0,20000)+
      xlab("Time of the Day")+
      ylab("Generation (MWh)")+
      guides(fill=guide_legend(title="Fuel Type"))
  })
  output$slider <- renderUI ({
    sliderInput("Date",
                "Date:",
                min = as.Date("2009-01-01","%Y-%m-%d"),
                max = as.Date("2022-03-31","%Y-%m-%d"),
                value = input$Date_calendar, timeFormat="%Y-%m-%d",
                step = 1,
                animate = animationOptions(interval = 400,
                                           playButton = icon("play", "fa-2x"),
                                           pauseButton = icon("pause","fa-2x" ))
    )
  })
}

# Run the application 
shinyApp(ui = ui, server = server)

logs when publishing:

2022-05-07T05:30:38.347878+00:00 shinyapps[6252822]: Running on host: 94e2e8808437
2022-05-07T05:30:38.347924+00:00 shinyapps[6252822]: Server version: 2022.03.1
2022-05-07T05:30:38.347959+00:00 shinyapps[6252822]: LANG: C.UTF-8
2022-05-07T05:30:38.347972+00:00 shinyapps[6252822]: Working directory: /srv/connect/apps/ERCOT_generation_shiny_app_dir
2022-05-07T05:30:38.348036+00:00 shinyapps[6252822]: R version: 4.0.5
2022-05-07T05:30:38.348084+00:00 shinyapps[6252822]: shiny version: 1.7.1
2022-05-07T05:30:38.348204+00:00 shinyapps[6252822]: rmarkdown version: (none)
2022-05-07T05:30:38.348148+00:00 shinyapps[6252822]: httpuv version: 1.6.5
2022-05-07T05:30:38.348261+00:00 shinyapps[6252822]: knitr version: (none)
2022-05-07T05:30:38.348308+00:00 shinyapps[6252822]: jsonlite version: 1.7.2
2022-05-07T05:30:38.348348+00:00 shinyapps[6252822]: RJSONIO version: (none)
2022-05-07T05:30:38.348395+00:00 shinyapps[6252822]: htmltools version: 0.5.2
2022-05-07T05:30:38.348434+00:00 shinyapps[6252822]: reticulate version: (none)
2022-05-07T05:30:38.348480+00:00 shinyapps[6252822]: Using pandoc: /opt/connect/ext/pandoc/2.16
2022-05-07T05:30:38.348523+00:00 shinyapps[6252822]: Using jsonlite for JSON processing
2022-05-07T05:30:38.348660+00:00 shinyapps[6252822]: Starting R with process ID: '26'
2022-05-07T05:30:38.348713+00:00 shinyapps[6252822]: Shiny application starting ...
2022-05-07T05:30:38.348757+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.348566+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.348807+00:00 shinyapps[6252822]: Attaching package: ‘rsconnect’
2022-05-07T05:30:38.348855+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.348914+00:00 shinyapps[6252822]: The following object is masked from ‘package:shiny’:
2022-05-07T05:30:38.348964+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349095+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349010+00:00 shinyapps[6252822]:     serverInfo
2022-05-07T05:30:38.349231+00:00 shinyapps[6252822]: The following objects are masked from ‘package:stats’:
2022-05-07T05:30:38.349051+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349181+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349282+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349135+00:00 shinyapps[6252822]: Attaching package: ‘dplyr’
2022-05-07T05:30:38.349410+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349367+00:00 shinyapps[6252822]:     filter, lag
2022-05-07T05:30:38.349464+00:00 shinyapps[6252822]: The following objects are masked from ‘package:base’:
2022-05-07T05:30:38.349673+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349769+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349515+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349564+00:00 shinyapps[6252822]:     intersect, setdiff, setequal, union
2022-05-07T05:30:38.349817+00:00 shinyapps[6252822]: The following objects are masked from ‘package:base’:
2022-05-07T05:30:38.349721+00:00 shinyapps[6252822]: Attaching package: ‘lubridate’
2022-05-07T05:30:38.349615+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349865+00:00 shinyapps[6252822]: 
2022-05-07T05:30:38.349919+00:00 shinyapps[6252822]:     date, intersect, setdiff, union
2022-05-07T05:30:38.349976+00:00 shinyapps[6252822]: 

I'm deeply frustrated as I cannot find out what went wrong. I've ensured relative path and required package library calls. Any insight is greatly appreciated!

[nirgrahamuk]

Could you format this into a reproducible example? That is a set of code or rstudio.cloud project that folks can easily get up and running to replicate your issue? Currently, this is only part of a shiny app.

IF you aren't familiar with best practices for shiny reprexes, check out

Shiny debugging and reprex guide

Shiny issues can be challenging to resolve relative to other problems with your code or statistical methods. Shiny apps are often large, complex projects with interacting files. When seeking help from others it is considered polite to: First, do your best to work through RStudio's debugging tools to diagnose your issue on your own. Often those shiny logs and tracebacks are useful to others trying to help out. Second, strive to minimize the effort required to replicate your issue. You can do this with a reproducible example ("reprex"). Shiny Debugging Errors in Shiny code can be difficult to track down. If you don't know where your problem is coming from, you can track it down with some o…

This will make it easier for folks to replicate your issue and offer suggestions to solve it.