Thanks, yes, i did. And just in case, I quit the rights, saved them, enabled the rights again and saved them.
I also thought, that if the rights aren't met, the payment method just doesn't show, but it does.
But it might be something like that, that somehow something broke in the update proces, for which reason Prestashop shows the module in the ultimate page, but when going to the module denies that right. But where and how do I find what goes wrong there?