Why won't my Barplot display?

...I created a program to display a Barplot. It worked. When I incorporate that code into one of the tabs in a larger program, I can not be the bar chart to display. Can someone see where I went wrong?

SERVER

# Reading data set
my_data=read.table("hack.csv", header=T, sep=",")
#number of row of data
my_data$Year=as.factor(my_data$Year)
server <- function(input, output) {
  ## Information for dashboard tab 
  # Reading data set
  my_data=read.table("hack.csv", header=T, sep=",")
  #number of row of data
  my_data$Year=as.factor(my_data$Year)
  
  server <- function(input, output) {
     
    ## Information for data tab
    # data table output
    
    output$da.tab <- DT::renderDataTable(datatable(my_data, extensions = 'Buttons',
                                                   style = "bootstrap",
                                                   filter = list(position = 'top', clear = T, plain = F),
                                                   options = list(pageLength = 1500, dom = 'Bfrtip', 
                                                                  buttons = 
                                                                    list('copy', 'print', list(
                                                                      extend = 'collection',
                                                                      buttons = c('csv', 'excel', 'pdf'), 
                                                                      text = 'Download')
                                                                    )  ) )    )  }
  ## Information for data tab
  # data table output
 
  output$da.tab <- DT::renderDataTable(datatable(my_data, extensions = 'Buttons',
                                                 style = "bootstrap",
                                                 filter = list(position = 'top', clear = T, plain = F),
                                                 options = list(pageLength = 1500, dom = 'Bfrtip', 
                                                                buttons = 
                                                                  list('copy', 'print', list(
                                                                    extend = 'collection',
                                                                    buttons = c('csv', 'excel', 'pdf'), 
                                                                    text = 'Download')
                                                                  )
                                                 )  )  )
  
  
  #This is used to create the BarPlot
  server <- function(input,output){
    
    reactive_data = reactive({
      #Reading from the datbase for year selected
      selected_year = as.numeric(input$YEAR)
      return(data[data$year==selected_year,])
      
    })
    #outputting the bar data
    output$bar <- renderPlot({
      color <- c("blue", "red", "yellow")
      
      our_data <- reactive_data()
      
      barplot(colSums(our_data[,c("CyberCrime","CyberWar","CyberHacks")]),
              ylab="Total",
              xlab="Census Year",
              names.arg = c("CyberCrime","CyberWar","CyberHacks"),
              col = color)
    })
  }}

UI

library(shiny)
library(shinydashboard)
library(ggplot2)
library(ggthemes)
library(DT)

# my data
my_data=read.table("hack.csv", header=T, sep=",")
# changing date to categorical data 
#my_data$Year=factor(my_data$Year)

## Preparing sidebar items
sidebar <- dashboardSidebar(
  width = 300,
  sidebarMenu(
    menuItem(h3("Dashboard"), tabName = "dashbd"),
    menuItem(h3("Data"), tabName = "datafile"),
    menuItem(h3("Visualization of Data"), tabName = "graphs", 
             menuSubItem(h4("- Barplot"), tabName = "crime")    ),
     br(),
    hr()
  )
)
## Preparing for the body items
body <- dashboardBody(
  tabItems(
    tabItem(tabName = "dashbd",
            fluidRow(
              valueBoxOutput("vbox1", width = 6),
              valueBoxOutput("vbox2", width = 6)),
            h2("Introduction",  align = "center", style = "font-family: 'times'; color:blue"),
            h3("Cyber crime damage costs to hit $6 trillion annually by 2021. It all begins and ends with cyber crime. Without it, there's nothing to cyber-defend. The cybersecurity community and major media have largely concurred on the prediction that cyber crime damages will cost the world $6 trillion annually by 2021, up from $3 trillion in 2015. This represents the greatest transfer of economic wealth in history, risks the incentives for innovation and investment, and will be more profitable than the global trade of all major illegal drugs combined"),
            fluidPage(
              fluidRow(
                column(
                  h2("About this app ...", align = "center", style = "font-family: 'times'; color:blue"),
                  h3("This app helps you to explore and visualize the motivation behind cyber attacks
                     I have used the database available",  a("here.",href="https://www.hackmageddon.com/about/"), 
                     style = "font-family: 'times'"),
                  width = 4,
                  align = "left"
                  
                ),
                column(
                  h2("How to use!", style = "font-family: 'times'; color:blue"),
                  h3("This app contains multiple sections;  the database and several visual graphs. ", 
                     style = "font-family: 'times'"),              
                  width = 8,
                  align = "left"
                ),
                br(),
                br()
                )
            ),
            p()
    ),  
    tabItem(tabName = "datafile",
            box(title = "Motivation of Cyber Attacks in Italy",
                width = 12, 
                DT::dataTableOutput('da.tab'))  
    ),
    
    #the select for barplot
    tabItem(tabName = "crime",
            titlePanel(title = h4("Cyber Attacks in Italy by Year", align="center")),
            sidebarPanel(
              
              radioButtons("YEAR", "Select the Census Year",
                           choices = c("2017", "2016", "2015","2014"),
                           selected = "2017")),
            
            
            sidebarPanel(
              plotOutput("MyBar"))
    )
            
        
  )  )

# Show a plot of the generated distribution
## Putting them together into a dashboardPage

ui <- dashboardPage( 
  skin="blue",
  # add this -> navbarMenu()
  dashboardHeader(
    title="MOTIVATION BEHIND CYBER ATTACKS IN ITALY",
    titleWidth = 550,
    tags$li(class = "dropdown"
    )
  ),
  sidebar,
  body
)

DATA FILE HACK.CSV

YEAR,CyberCrime,CyberHacks,CyberEspionage,CyberWar
2014,45,26,9,6
2015,55,38,10,9
2016,65,45,12,2
2017,60,55,9,1