Could not compile application class

[Andrew Henshaw]

Does anyone have any ideas when I get a messagebox with 'Could not compile application class’ in it when I try to save an app so I can deploy it on an iPhone,  and at the same time I get a another window popping up saying I need Java runtime environment.

Its frustrating as its only on one app,  everything else works fine but there is nothing special in the app,  the build settings are exactly same as another than compiles file,  it has no included files,  im at a loss.