Can't download Bubbleplot/Heatmap

[scriptbotprime]

I have several ShinyCell apps hosted on a Shiny-Server. Everything works fine until I try to download the plot in the Bubbleplot / Heatmap tab. In all other tabbs this is not a problem. I tried changing gene sets, plot type, color schemes, plot size etc. but couldn't solve the problem.

When running the app in RStudio this issue doesn't occur.

This is the content of the server logs:

su: ignoring --preserve-environment, it's mutually exclusive with --login

Listening on http://127.0.0.1:41203

Attaching package: ‘DT’

The following objects are masked from ‘package:shiny’:

    dataTableOutput, renderDataTable

Warning: Navigation containers expect a collection of `bslib::nav_panel()`/`shiny::tabPanel()`s and/or `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer` if you wish to place content above (or below) every panel's contents.
Warning: Navigation containers expect a collection of `bslib::nav_panel()`/`shiny::tabPanel()`s and/or `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer` if you wish to place content above (or below) every panel's contents.
Warning: Navigation containers expect a collection of `bslib::nav_panel()`/`shiny::tabPanel()`s and/or `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer` if you wish to place content above (or below) every panel's contents.
Warning: Navigation containers expect a collection of `bslib::nav_panel()`/`shiny::tabPanel()`s and/or `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer` if you wish to place content above (or below) every panel's contents.
Warning: Navigation containers expect a collection of `bslib::nav_panel()`/`shiny::tabPanel()`s and/or `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer` if you wish to place content above (or below) every panel's contents.
Warning: Navigation containers expect a collection of `bslib::nav_panel()`/`shiny::tabPanel()`s and/or `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer` if you wish to place content above (or below) every panel's contents.
Warning: Navigation containers expect a collection of `bslib::nav_panel()`/`shiny::tabPanel()`s and/or `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer` if you wish to place content above (or below) every panel's contents.
Warning: Navigation containers expect a collection of `bslib::nav_panel()`/`shiny::tabPanel()`s and/or `bslib::nav_menu()`/`shiny::navbarMenu()`s. Consider using `header` or `footer` if you wish to place content above (or below) every panel's contents.
Warning: Error in if: missing value where TRUE/FALSE needed
  107: args_regularity_evaluation
  106: h5data$read
  105: scDRnum [/apps/INKILL_NK/server.R#157]
  104: exprFunc [/apps/INKILL_NK/server.R#705]
  103: widgetFunc
  102: ::
htmlwidgets
shinyRenderWidget
  101: func
   88: renderFunc
   87: renderFunc
   83: renderFunc
   82: output$sc1a1.dt
    1: runApp
Warning: The `size` argument of `element_line()` is deprecated as of ggplot2 3.4.0.
ℹ Please use the `linewidth` argument instead.
Warning: Error in <Anonymous>: cannot open file 'Rplots.pdf'
  1: runApp
Warning: Error in <Anonymous>: cannot open file 'Rplots.pdf'
  1: runApp

Whenever I click the download button the following line is added to the log: Warning: Error in : cannot open file 'Rplots.pdf'