I get an error when I try to add a participant

If you get a prompt like "This number has chosen to unsubscribe from messages," it means that they had texted STOP at some point in the past. Remind can't send messages to that number. We can't unblock the number, but that participant can! They should instead join by texting the class code to the Remind number, 81010. 

If you get a prompt like "The number cannot be added to this class," it could be due to:

• A student under the age of 13 isn't allowed to join a class that is owned by another student or parent. 
• A student under the age of 13 isn't allowed to join a class that hasn't been linked to a school. 
• The user has been banned from the school organization.
• The user has been blocked by the owner of the class.