We are on 10.3 , Implemented Oauth sign in to the community ,By creating a plugin using IOAuthClient Authentication.
By creating Oauth Link for each Users with clientid and clientype Id . Most probably its working fine for most of the users.
But there is an issues with the very old users who had already joined the community before implementing to Oauth sign in.
They are able to login successfully But on post login they are experiencing Error as .