The Reload App button to reload a running shiny app worked perfectly, but on updating to the newest RStudio ( RStudio Desktop 1.3.1056 for Windows), I get the error message:
Error Saving File
Exception caught: (TypeError) : Cannot read property 'id' of null
This happens for all of my shiny apps, even the Old Faithful one that comes "preshipped" when openeing a new shiny application (with ui.r and server.r files).
After the update, RStudio IDE seem to have a problem of writing the edited ui.r file to disc on pressing "Relaoad App" that wasn't there before.
After downgrading to Version 1.2.5042 the issue did not show up and everything worked fine.