PROBLEMS RESOLVED:

1. Admin Settings Template URL Error:
   - Fixed breadcrumb navigation in admin_settings.html line 14
   - Changed from: url_for('main.admin')
   - Changed to: url_for('main.admin_panel')
   - Matches actual route function name in routes.py

2. Registration Toggle Parameter Mismatch:
   - Fixed admin_users.html registration toggle JavaScript (lines 483-527)
   - Changed from using 'registration_disabled' parameter
   - Changed to using 'registration_enabled' parameter
   - Now matches the admin_registration_settings API endpoint format

3. Registration Toggle Logic Fix:
   - Updated toggle.checked logic to use registration_enabled directly
   - Fixed status text display to show correct enabled/disabled state
   - Corrected AJAX request payload to send registration_enabled boolean

TECHNICAL DETAILS:
- Both templates now use consistent parameter naming with the backend API
- Registration toggle in /admin/users now works correctly with database persistence
- Admin settings breadcrumb navigation no longer throws BuildError
- All admin interfaces now properly integrate with SystemSettings model

This resolves both reported issues:
- '/admin/settings give error' - Fixed URL endpoint mismatch
- 'registration settings in /admin/users keep to show as enabled' - Fixed parameter format