PHP Errors in Debug Log – Critical Error

Error Details
=============
An error of type E_ERROR was caused in line 553 of the file /var/www/motrati.com/htdocs/wp-content/plugins/stream/connectors/class-connector-widgets.php. Error message: Uncaught Error: Cannot unset string offsets in /var/www/motrati.com/htdocs/wp-content/plugins/stream/connectors/class-connector-widgets.php:553
Stack trace:
#0 [internal function]: WP_Stream\Connector_Widgets->callback_updated_option()
#1 /var/www/motrati.com/htdocs/wp-content/plugins/stream/classes/class-connector.php(127): call_user_func_array()
#2 /var/www/motrati.com/htdocs/wp-includes/class-wp-hook.php(324): WP_Stream\Connector->callback()
#3 /var/www/motrati.com/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#4 /var/www/motrati.com/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#5 /var/www/motrati.com/htdocs/wp-includes/option.php(1022): do_action()
#6 /var/www/motrati.com/htdocs/wp-content/plugins/advanced-database-cleaner-pro/includes/class_clean_options.php(349): update_option()
#7 /var/www/motrati.com/htdocs/wp-content/plugins/advanced-database-cleaner-pro/includes/class_clean_options.php(85): ADBC_Options_List->process_bulk_action()
#8 /var/www/motrati.com/htdocs/wp-content/plugins/advanced-database-cleaner-pro/includes/class_clean_options.php(34): ADBC_Options_List->aDBc_prepare_and_count_options()
#9 /var/www/motrati.com/htdocs/wp-content/plugins/advanced-database-cleaner-pro/includes/class_clean_options.php(585): ADBC_Options_List->__construct()
#10 /var/www/motrati.com/htdocs/wp-content/plugins/advanced-database-cleaner-pro/advanced-db-cleaner.php(856): include_once(‘…’)
#11 /var/www/motrati.com/htdocs/wp-includes/class-wp-hook.php(324): ADBC_Advanced_DB_Cleaner_Pro->aDBc_main_page_callback()
#12 /var/www/motrati.com/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#13 /var/www/motrati.com/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#14 /var/www/motrati.com/htdocs/wp-admin/admin.php(259): do_action()
#15 {main}
  thrown