I have deployed my shinyapp online and I am constantly checking my logs for possible problems. A warning message that often appears when some users connect to the platform is the following:
Warning: no DISPLAY variable so Tk is not available
and in general appears after the loading of the proto package, but I don't know if this is somehow related with the warning.
Do you have any idea of what this means and if it affects my application and hence some users cannot access to it? If yes, do I have to change something in my code or it depends to the user terminal?
I found an old post on Reddit related to your issue:
It seems from what I get from it that this is just a warning that appears when packages that expect a terminal/display are loaded. Since the shiny server themselves have no display/terminal your code has access to, that is probably what is generating the warning. It seems you can safely ignore or even suppress it.
I'm not a computer scientist nor an R expert, and I could be wrong, so someone on this forum might have a better explanation