Hi,
When you go back to the vote listing is your vote created ?
It should be, I just seen in the code that we have a little issue, we return false instead of true in one case and that's why it show error saving instead of success, but it is working fine.
If it is not in the listing, so that's potentially because you missed to fill a mandatory field, for example in your vote and comment settings if you selected "vote and comment connected" so you have to fille the vote field AND the comment field.