Hi,

This is almost always caused by a misconfigured proxy_mode setting. Try these in order:

1. Open your odoo.conf file and make sure this line is not set to True unless you're actually behind a reverse proxy:

   proxy_mode = False
   

2. If you don't have a conf file, start Odoo with:

   --proxy-mode=False
   

3. Also check that xmlrpc_interface and netrpc_interface are not forcing unexpected redirects.

4. Clear cookies and browser cache, or try an incognito window.

5. If the issue started after selecting a database from the manager, try accessing the database directly: http://localhost:8069/web?db=your_database_name

The root cause is Odoo receiving a forwarded HTTPS header while running plain HTTP, causing an infinite HTTP↔HTTPS redirect loop. Disabling proxy_mode resolves it for local installations.