WordPress Login

Hey people,

I tried Setting up auth0 on a webpage for a friend of Mine in politics and I encounter a Problem That After a successful Login the Redirect brings me to an error Page at wordpress which slightly Confuses me cause I don’t know what to do. I already put Cloudflare Caching Rules on it, looked for Firewall Events but nothing gets better.

The error Message is Seen in the pic

Is There anybody knowing how to fix That?

Thank you for your help in advance peoples!