I am also having the same (or a similar) problem with the Google Voice Helper. I have attached an aia file that works (can send text messages) on a Samsung Galaxy Note 4 (SM-N901T3) but does not work on a Galaxy S4 (SGH-M919). Both were connected via USB when running App Inventor under Chrome.
It seems like the same code fails on one device (GvHelper Error) and works on the other. Another possible clue is that even when GoogleVoiceEnabled is changed to false, the development device show the "Finished Authentication" alert message. Why is it authenticating when GoogleVoiceEnabled=false? Could that have something to do with it?
Finally, perhaps my Google Voice account is somehow screwed up. Is there a way to verify it that I can share with my students?
Thanks for any insight that you can provide,
r