Hello,
I just set-up Oauth2 for LinkedIn authentication and I had the same message.
After long search on forum, I decided to review the settings :
My LinkedIn App was in dev mode, so I changed it to Live.
The configuration on the Oauth2 for LinkedIn in Moodle had the Authenticate token requests via HTTP headers checked, so I removed it.
Now, it work fine.
Hope this help,
Ludovic
PS: Is there a way to have the person log in with Oauth and have the account validated automatically without the e-mail and the link to confirm ? This is to enable faster access to the materials.
