WordPress action admin_post for non-admin authenticated users – Form submission

I found that the issue was due to another plugin on my site. After deactivating it, everything works well. So, the action admin_post is used for all authenticated users( admins and non-admins ).

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)