Errors after date

Hi all,

It seems that after the update of last night, I run into the following error. Anyone who might be able to point me in the right direction aka help me resolve this?

Thanks,
SK.

2018-07-04T21:02:10+00:00 CRITICAL Uncaught Exception: Serialization of ‘Closure’ is not allowed in /mnt/web319/d3/25/59221925/htdocs/WordPress_SecureMode_01/wp-content/plugins/mollie-payments-for-woocommerce/includes/mollie/wc/helper/data.php:335
Stack trace:
#0 [internal function]: ArrayObject->serialize()
#1 /mnt/web319/d3/25/59221925/htdocs/WordPress_SecureMode_01/wp-content/plugins/mollie-payments-for-woocommerce/includes/mollie/wc/helper/data.php(335): serialize(Object(Mollie\Api\Resources\MethodCollection))
#2 /mnt/web319/d3/25/59221925/htdocs/WordPress_SecureMode_01/wp-content/plugins/mollie-payments-for-woocommerce/includes/mollie/wc/helper/data.php(294): Mollie_WC_Helper_Data->getApiPaymentMethods(true, true)
#3 /mnt/web319/d3/25/59221925/htdocs/WordPress_SecureMode_01/wp-content/plugins/mollie-payments-for-woocommerce/includes/mollie/wc/helper/data.php(263): Mollie_WC_Helper_Data->getRegularPaymentMethods(true, true)
#4 /mnt/web319/d3/25/59221925/htdocs/WordPress_SecureMode_01/wp-content/plugins/mollie-payments-for-woocommerce/inclu

The page I need help with: [log in to see the link]