Soft Reject Theme Raises Issues

Greetings guys,

I have submitted a theme not long ago and got reject on some issues, all were clear except for the following:

Please make sure that your template doesn’t raise any PHP errors, notices or warnings. Enabling wp_debug can

I have tried enabling wp_debug and php.ini to display all warnings/errors and still can’t find it to popup for me.

Could someone explain where this problem even exists, so that I can try solving

You should try to install a fresh site to check. Some errors do not appear in developing site (which has all option values in database)