bbPress.org

Then I’m really out of ideas 🙁

What you could do is just delete all of it and restart from scratch : https://codex.bbpress.org/getting-started/testing-your-bbpress-installation/creating-a-test-site/

There is something wrong with your local installation… I have never created a local one, but immediately went to a provider to have an account (even the very basic one). Maybe someone else has some ideas here.

Pascal.