How to avoid damaging HP 39gs Aplet

If you have difficulty running an Aplet, this is what may have happened.

User received the aplet successfully for a colleague. He start the aplet and selected "Choose function":

But instead of selecting the FN and press the {Ok} key.
He may have pressed {CANCEL} key.

And the following option will appear.

He may then have pressed {YES} key which would have bring him to the program edit mode.

May have got disoriented. Not know what to do next, he may have tried to exit screen by pressing {STO} key and [Enter] key.

He then pressed [APLET] to exit the screen, but by then the aplet is damaged (wrongly edited).

When he tried to ro run the aplet, he will get the following screen...

As the aplet has been damaged, he will not be able to proceed.

What he have to do is to delete the aplet and download it again.