Facebook Permission Expiry
Your Facebook permission in Boxify can expire when Facebook invalidates the connection token (a security key) due to a security-related event. When this happens, Boxify loses the ability to send messages or receive data from your Page.

How to fix it
Section titled “How to fix it”-
Log out of the Boxify system.
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Ask the person with the Facebook Page admin role to log in to Boxify again using the Login with Facebook button.

Logging back in issues a fresh token, which restores messaging and data from your Page.
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