After I deploy my R shiny App in web server, it produced such errors. Can anyone help me to solve it? Thanks. 

This error is very weird. I can run it in Shiny web server (<http://www.shinyapps.io/>). But I can not run it on my own web server. I commented out the code which produce pdf. But the error is still existing. 

su: ignore --preserve-environment, it's mutually exclusive to --login.

Listening on <http://127.0.0.1:37436>
Warning: Error in : cannot open file 'Rplots.pdf'
 48: 

Execution halted