There is existing code for showing error messages. This is a bug that can be fixed.
Proposed fix:
Fix the areas in the code that is causing the bug and have the predefined error messages display successfully on the Log in page for both customer log in and admin log in.
Steps to reproduce this issue:
Start the server and go to the user registration page http://localhost:8080/.
Enter non-existing username and password and click Login.
Similar issue for admin log in. For example, go to a page that requires admin access such as customers page http://localhost:8080/admin/customers
Reason this is a problem:
There is existing code for showing error messages. This is a bug that can be fixed.
Proposed fix:
Fix the areas in the code that is causing the bug and have the predefined error messages display successfully on the Log in page for both customer log in and admin log in.