Doesn't save settings

Hi,

I have a problem with saving the settings on Woocommerce > Settings > Payment Methods > iDeal Pronamic. When I select the method I created (ABN AMRO Easy) and save, it jumps back to nothing ‘select configuration’.

I get this error:

...cm7/wp-content/plugins/pronamic-ideal/classes/Pronamic/WooCommerce/IDeal/IDealGateway.php on line 185 {"result":"failure","messages":"","refresh":"false"}

I hope you can help me out. Thanks!

http://ww.wp.xz.cn/extend/plugins/pronamic-ideal/