"Authentication failed! Facebook returned an invalid user id." in Facebook pugin

Hello, suddenly this problem started happening.

I am using Facebook plugin in Community Builder but when I press the "login with Facebook" button, Facebook is loaded but on return, a 500 error is thrown with the message: "5 - Authentication failed! Facebook returned an invalid user id."

The URL of the final script is: " hum.devx.cl/area-privada/pluginclass.html?plugin=cbconnect&provider=facebook&action=authenticate&return=aHR0cDovL2h1bS5kZXZ4LmNsL2NvbXBvbmVudC9jb21wcm9maWxlci9sb2dpbi5odG1s#_=_ ".

This does not work since about 1 week. I have spent 2 days trying to figure this out, but I am almost giving up.

Can you give me some insights, please?

My last attempt was to dig into "base_facebook.php" file and I realized that the "signed_request" parameter is not being received. I don't know if this is normal or not.

Thanks a lot in advance. My brain is about to explode.

Regards
Jaime

CB Connect has long since been rewritten with its own provider APIs instead of depending on 3rd party APIs. It does not include or use base_facebook.php anymore. Your issue is likely entirely due to being out of date.