Compile window hangs if browser is unable to reach the Cloud Compiler

[zfi]

The Compile dialog window posts an initial "Compile" message but does not react when the application is unable to reach the Cloud Compiler container. The console log does indicate that a failure has been detected:

16:21:07.418 Compiler error: Failed to fetch
instrument.js:109 16:21:07.420 (PTC) Error while compiling
instrument.js:109 16:21:07.420 (PTC) Message: Cannot read property 'success' of undefined

The UI should provide some indication that the compile failed due to a connectivity issue and the the compilation itself has not been performed.

ideally, the compile button should be inactive if the Cloud Compiler is unreachable. Employing a heartbeat could generate significant traffic if there are hundreds of users online simultaneously. Perhaps a better option is to ping the Cloud Compiler after the "Compile" button is clicked and the Compile dialog is opened, but before the first "Compile" output.