jquery.js?ver=1.12.4:4 POST /wp-admin/admin-ajax.php 500 ()

Здравствуйте! Подскажите пожалуйста куда копать? Случилось необычное) Обновила WP-Recall и Partners System и вот что получилось у меня... при регистрации нового пользователя приходит сообщение ну и как полагается заходим по вкладке "ТЫ-партнер" а там новый партнер не отображается. Далее если активировать "Промокоды" и ещё раз зайти на вкладку "ТЫ-партнер" то:

jquery.js?ver=1.12.4:4 POST https://site.com/wp-admin/admin-ajax.php 500 ()
send @ jquery.js?ver=1.12.4:4
ajax @ jquery.js?ver=1.12.4:4
rcl_ajax @ core.js?ver=16.7.3:532
(anonymous) @ scripts.js?ver=16.7.3:54
dispatch @ jquery.js?ver=1.12.4:3
r.handle @ jquery.js?ver=1.12.4:3

Заранее спасибо за ответ!

PHP message: PHP Warning:  Illegal offset type in isset or empty in /var/www/html/wp-content/plugins/wp-recall/add-on/user-balance/index.php on line 43" while reading response header from upstream, client: 166.62.39.5, server: site.com, request: "GET /cgi-bin/temp.php HTTP/1.1", upstream: "fastcgi://unix:/run/php/php7.0-fpm.sock:", host: "site.com", referrer: "site.com"

2017/10/07 18:02:31 [error] 13795#13795: *473 open() "/var/www/html404" failed (2: No such file or directory), client: 166.62.39.5, server: site.com, request: "GET /cgi-bin/temp.php HTTP/1.1", host: "site.com", referrer: "site.com"
2017/10/07 18:02:31 [error] 13795#13795: *473 FastCGI sent in stderr: "PHP message: PHP Warning:  call_user_func_array() expects parameter 1 to be a valid callback, function 'register_taxonomy_donate' not found or invalid function name in /var/www/html/wp-includes/class-wp-hook.php on line 298

PHP Deprecated:  Non-static method Wallet_Output_History_Table::update_status_request() should not be called statically in /var/www/html/wp-includes/class-wp-hook.php on line 298
[09-Oct-2017 08:27:39 UTC] PHP Notice:  Undefined property: stdClass::$subtab_id in /var/www/html/wp-content/plugins/wp-recall/functions/ajax.php on line 37
[09-Oct-2017 08:27:39 UTC] PHP Fatal error:  Uncaught Error: Call to undefined function bcdiv() in /var/www/html/wp-content/plugins/wp-recall/add-on/partners-system/classes/class-hash.php:55
Stack trace:
#0 /var/www/html/wp-content/plugins/wp-recall/add-on/partners-system/classes/class-hash.php(25): Hash36->modInverse('1', 99990001)
#1 /var/www/html/wp-content/plugins/wp-recall/add-on/partners-system/promocode.php(63): Hash36->encode('1')
#2 /var/www/html/wp-content/plugins/wp-recall/add-on/partners-system/index.php(85): ps_get_promocode('1')
#3 /var/www/html/wp-content/plugins/wp-recall/classes/class-rcl-sub-tabs.php(111): ps_tab_refers('1')
#4 /var/www/html/wp-content/plugins/wp-recall/classes/class-rcl-sub-tabs.php(51): Rcl_Sub_Tabs->get_subtab('1')
#5 /var/www/html/wp-content/plugins/wp-recall/classes/class-rcl-tab.php(98): Rcl_Sub_Tabs->get_sub_content('1')
#6 /var/www/html/wp-content/plugins/wp-recall/classes/class-rcl-tab.php(221): Rcl_Tab->get_tab_content('1', NULL)
#7 /var/www/html/wp-content/plugins/wp-recall/rcl-functions.php(150): Rcl_Tab->g in /var/www/html/wp-content/plugins/wp-recall/add-on/partners-system/classes/class-hash.php on line 55

Спасибо вам огромное! Установила

sudo apt-get install php7.0-bcmath