I am on Drupal 7.51 / CiviCRM 4.7.12
I have just installed Twilio (SMS) Extension, purchased a number (+33... (France) from Twilio), upgraded my account, and configured Twilio Extension accordingly (as per https://wiki.civicrm.org/confluence/display/CRMDOC/Setting+up+a+SMS+Provider+for+CiviSMS) : filling username and password with the LIVE API Credentials specified at https://www.twilio.com/console/account/settings.
When I test it (on a test Group), I get the following Error Message :
The selected contacts have no valid phone, or prefer not to receive SMS, or are deceased.
(I did not configure inbound SMS)
Any suggestion would be welcome