Can't enter the background

Question

The username is correct

The password is correct

The verification code is correct

The database connection is correct

The prompt [OK] will appear

But

But

But

I can’t log in when I click the login button, why

Answer 1

Attach code + picture. The problem can be clearly understood

Answer 2

If you ask a question like this, no one can answer it. How did you achieve it? What is the main code? What is the error message?

You didn’t say anything, just that you couldn’t log in...