Error in file(file, "rt") : cannot open the connection - Shiny - r

Question

I've been trying to add a graph I made to my shiny layout but when I run the project it shows me this error.
I've got the following code for the serve.R:
library(shiny)
df <-read.csv('./CSV/data.csv')
shinyServer(function(input, output) {
output$scatterPlot <- renderHighchart({
hchart(df, "scatter",
hcaes(x=df$revenue,y=df$users,group=df$name_group))
})
})
And for the ui I got:
library(shiny)
library(shinydashboard)
library(shinycssloaders)
titlePanel("my_app")
header <- dashboardHeader(title = "my_app" )
sidebar <- dashboardSidebar(
sidebarMenu(
menuItem("Overview", tabName = "overview", icon = icon("book-open"))
)
body <- dashboardBody(
tabItems(
tabItem("overview",
fluidRow(
box(
title = "revenue_vs_user", status = "primary",
withSpinner(highchartOutput("scatterPlot"))
))
)
))
shinyUI(dashboardPage(header, sidebar, body, skin = "blue"))
All answers I've seen on this mistake say that it happens because the data is not being read correctly but in my enviroment variables the data appears, so it is being read. Thanks for the help!

Answer 1

I had the same problem. When developing the app and testing if the CSV would upload, R studio showed the CSV data properly uploaded and stored in the Environment variables. But when I would select Runn App, I would get the same error.
I also use a data sub-folder structure. I also setup an R Project in the folder above my app. So the folder structure looked like this:
./Project/app/data
where the Project file was in the Project folder, app.R file was in the app folder, and the CSV I was trying to upload was in the data folder.
I then tried putting the Project file in the app folder instead. I also updated the relative file path for read.csv in the app to reflect the new working directory. For some reasons this worked. I don't know why.