Example:

1. have some json error(s) on the editor
2. execute option [Check JSON syntax now]
3. ok: bottom popup "Syntax errors in JSON" shows errors.
4. fix errors on editor
5. execute again option [Check JSON syntax now]
6. nok: bottom popup "Syntax errors in JSON" still showing previous errors.

Would be nice to at least clear "Syntax errors in JSON" pane.

and/or add success No errors found (in beautiful green color) :)