I have one user that said he can’t login. If I go to the users, I can’t find him.
If I try to add him manual, Auth0 tells me that the user already exists.
Anything I can do to find the user and send him a password reset, or delete him soo het can create a new account?
Hey there 
Is this a database connection user? If you have their email handy, you can try fetching their account using the Management API via the GET /api/v2/users-by-email endpoint (which is immediately consistent): Auth0 Management API v2
You can delete the user by their email using the DELETE /api/v2/connections/{id}/users endpoint and re-creating their account: Auth0 Management API v2
This might be a case where there is an indexing delay. Let me know if this works for you!
His email is REDACTED
Sorry, the option to Fetch like you discribe is out of my legue. I had my programmer to setup the app and Auth0 but he only worked on project base. I can get him again but that sounds like a lot of work, just to find one user. Can you see if you can find him and delete him, so het can register again?
I edited your post to remove your user’s email. I’ll send you a DM and we can walk through this 