com.restfb.exception.FacebookOAuthException: Received Facebook error response of type OAuthException: Error validating access token: The session has been invalidated because the user changed their password or Facebook has changed the session for secu

[Swati Sen]

Hi All,

I am having a weired experience while creating a messenger chatbot. the GET method of restfb returns that my webhook is verified after I added the callbackURL and verify token in my facebook app but whenever I am trying to test the bot with a message, the POST method is always returning 

"com.restfb.exception.FacebookOAuthException: Received Facebook error response of type OAuthException: Error validating access token: The session has been invalidated because the user changed their password or Facebook has changed the session for security reasons. (code 190, subcode 460) 'null - null'" 

I have logged out of all tabs from Facebook and logged in again and then created a new app and new page, generated the page access token , Facebook verified my webhook through GET method, still chatting with bot shows this error. Any solution pls?

Appreciate it.