shiny 使用shiny自带的代码也加载不出可视化图片只能加载按钮

LEOrose

问题描述：
我新建了一个shiny web app进入之后它有一个自带的代码如下，我运行之后只显示了按钮，图片不显示，然后我又使用了shiny自带的第一个代码也是出现这个问题
我的代码、运行结果如下

# This is a Shiny web application. You can run the application by clicking
# the 'Run App' button above.
#
# Find out more about building applications with Shiny here:
#
#    http://shiny.rstudio.com/
#

library(shiny)

# Define UI for application that draws a histogram
ui <- fluidPage(

    # Application title
    titlePanel("Old Faithful Geyser Data"),

    # Sidebar with a slider input for number of bins 
    sidebarLayout(
        sidebarPanel(
            sliderInput("bins",
                        "Number of bins:",
                        min = 1,
                        max = 50,
                        value = 30)
        ),

        # Show a plot of the generated distribution
        mainPanel(
           plotOutput("distPlot")
        )
    )
)

# Define server logic required to draw a histogram
server <- function(input, output) {

    output$distPlot <- renderPlot({
        # generate bins based on input$bins from ui.R
        x    <- faithful[, 2]
        bins <- seq(min(x), max(x), length.out = input$bins + 1)

        # draw the histogram with the specified number of bins
        hist(x, breaks = bins, col = 'darkgray', border = 'white')
    })
}

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

QQ图片20201213103500.png

### !我的系统环境如下
`sessionInfo()
R version 4.0.2 (2020-06-22)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18363)

Matrix products: default

locale:
[1] LC_COLLATE=Chinese (Simplified)_China.936  LC_CTYPE=Chinese (Simplified)_China.936   
[3] LC_MONETARY=Chinese (Simplified)_China.936 LC_NUMERIC=C                              
[5] LC_TIME=Chinese (Simplified)_China.936    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] shiny_1.5.0

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.5      digest_0.6.25   withr_2.3.0     later_1.1.0.1   mime_0.9        plyr_1.8.6      R6_2.5.0       
 [8] xtable_1.8-4    jsonlite_1.7.1  magrittr_1.5    stringi_1.5.3   rlang_0.4.7     reshape2_1.4.4  promises_1.1.1 
[15] Cairo_1.5-12.2  tools_4.0.2     stringr_1.4.0   httpuv_1.5.4    fastmap_1.0.1   compiler_4.0.2  htmltools_0.5.0