getting error after installing the plugin

i am getting error after installing this please help i have added the error code i am getting in my dashboard please let me know if you think these codes are helpful for hacker to inter into my website i will delete it because i don’t have idea about this
please check and let me know the issue
y() expects parameter 1 to be a valid callback, class ‘RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home3/gomahamaya/public_html/wp-content/plugins/affiliate-coupons/vendor/meta-box/inc/field.php on line 523

Warning: call_user_func_array() expects parameter 1 to be a valid callback, class ‘RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home3/gomahamaya/public_html/wp-content/plugins/affiliate-coupons/vendor/meta-box/inc/field.php on line 523

Warning: call_user_func_array() expects parameter 1 to be a valid callback, class ‘RWMB_Fancy_Category_Field’ does not have a method ‘normalize’ in /home3/gomahamaya/public_html/wp-content/plugins/affiliate-coupons/vendor/meta-box/inc/field.php on line 523

Warning: call_user_func_array() expects parameter 1 to be a valid callback, class ‘RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home3/gomahamaya/public_html/wp-content/plugins/affiliate-coupons/vendor/meta-box/inc/field.php on line 523

Warning: call_user_func_array() expects parameter 1 to be a valid callback, class ‘RWMB_Dropdown_Pages_Field’ does not have a method ‘normalize’ in /home3/gomahamaya/public_html/wp-content/plugins/affiliate-coupons/vendor/meta-box/inc/field.php on line 523

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