sicco

Het probleem lag toch bij Mollie zelf en is inmiddels opgelost!

Hi Bet,

In the end the fix was simple. I overlooked one of the options of WordPress HTTPS (SSL). I network activated the plugin and then in the settings of the plugin only checked the Force SSL Exclusively option for the one WordPress MU site that uses HTTPS. This switches all http references on the requested webpages to https. I also made sure that my certificate is valid for both the ‘internal’ WordPress MU site address and the URL specified using the Domain Mapping plugin, because some links on the webpages use the internal URL and the certificate should thus be valid for those as well to avoid mixed content problems.

I still face a few problems though. When I use the WordPress HTTPS (SSL) plugin to force the admin part of the website to use HTTPS I still get mixed content problems, so I’m still figuring that out. Also when adding images to posts/pages in the visual text editor using a HTTPS link results in mixed content problems, so I use HTTP links for images (as they will be corrected by WordPress HTTPS (SSL) anyway when people retrieve the actual webpage).