hi,
division by zero errors that's probably because your warnings_options table is empty run this query in phpMyAdmin then set your AWS options and see if it get's saved after that those error messages should disappaer
Code:
INSERT INTO `".TABLE_PREFIX."warning_options` values ('1','3.0.8', 'No', 'No','No','No','','','','7','10','10','8','','','8','','No','3','0','All','No',' No','No','No','No','No','15')
replace "TABLE_PREFIX" with your own ...