This usually happens because of plugin/theme conflicts.
1. Login redirect not working.
How does the users login to your site? Do you have a separate login screen or do they use wp-login.php? Can you try the login through wp-login.php and see if the redirect works.
2. Navigation menu fields missing with warning.
If you click more information within the warning, it will take you to the documentation which explains how to work around it.
Take a look into the last section within the documentation.
You basically need to identify from where the conflict is coming. It could be a plugin or your theme. Disable all plugins except the User Role Editor Pro. Check if the warning still exists. If it is, then it is coming from your theme. Change the theme to a different theme and make sure you don’t see the warning. If you don’t see the warning, then you should see the fields in navigation menu. Set your permissions the way you want, after that you can change your theme back to the original and activate all plugins. You won’t see the fields after that, but your permissions will still work.