Why can't I reply to a Facebook message in Inbox?
If you receive the error message Unable to send Facebook message when replying to a Facebook message in Inbox, it’s for one of the following reasons, as defined in Facebook’s Messenger Platform Policy:
- The Facebook user sent you a private message, and you did not respond within 24 hours.
- The Facebook user left a comment on your Page, and you did not reply with a private message within 7 days.
- The Facebook user blocked or muted your conversation.
For more information, see Facebook’s Messenger Platform Policy Overview.