Update 6.501 issue a loop crash message

On my tablet Lenovo TAB7, OS Android 7, the K-9 Mail version 6.501 send a looping message of crashing in the app (see photo below). I had to shoot through a video (and after cutting image), because the message appears only for a few milliseconds.

To workaround I was forced to reinstall the stable version 6.400 and any work’s fine.