Show a nice message instead of an error if trying to load an unavailable screen (#2207)
Show a nice message instead of an error if trying to load an unavailable screen (#2207)

* Show a nice message instead of an error if trying to load an unavailable screen

* Tweak message
flutter/devtools,flutter/devtools,flutter/devtools,flutter/devtools,flutter/devtools,flutter/devtools,flutter/devtools,flutter/devtools,flutter/devtools