Hi bartolla,
We are not facing such problem. That means you have customized the code. While customizing the code did you create a child theme and then customized the code or you made direct changes in the code? If you made a direct change in the code then while updating to new version all your customized code will be lost. So we always recommended you to create a child theme before making any changes on it.
The above error Cannot redeclare attitude_add_editor_styles() (previously declared in /home/analyzei/public_html/wp-content/themes/attitude/library/functions/functions.php:58) in /home/analyzei/public_html/wp-content/themes/attitude/library/functions/functions.php on line 57 you are facing because it has been declared more than one time. You cannot redeclare twice the same functions.
Download the fresh copy of attitude theme and try it.
Thank you!