Google/Voice

Google Voice
Google Voice - https://www.google.com/voice

An error has occurred during signup
If you’re a new Google Voice user and encounter “An error has occurred” during forwarding phone verification it means one of two things: 1) Your carrier isn’t approved and you’ll want to try a new forwarding phone with a different carrier to complete the sign-up process 2) We accidentally missed your carrier when putting together our list of approved carriers -- if you believe this is the case please create a new topic to let us know about your specific scenario so the team can investigate.

Updates to new Google Voice user sign-up - Google Product Forums - https://productforums.google.com/forum/#!topic/voice/YXhUZGnwzYw