Local file uploads in
Shiny are very experimental. I have had success using this
feature from the latest version of Firefox but, at the time of writing, it
does not seem to be working from Chrome or IE.
If you have trouble using this feature but want to analyze your own
dataset, you can upload the file to a public URL using a tool like
Dropbox or one of the many free upload
It seems that any attempt at remote file uploads actually crash the app for all
users and cause a momentary downtime for the whole application -- so please attempt this feature
sparingly for the sake of anyone else viewing the application.