Thanks a lot for your help guys and sorry for the false alarm, maybe the plugin in Github should have this warning. I know that is a dumb mistake and most of web developers may be aware of it but just in case.
Hi, we deleted nginx config by mistake and the forum broke down
Now it is solved but users cannot login. Nodebb says : We were unable to log you in, likely due to an expired session. Please try again
Even the administrator cannot login