Hello,
your plugin insert a wrong url for verification in the verification mail.
I think your plugin will insert http:// before the main url from general wordpress config. So my normal domain (rechable) is https://www.nrw-carcoding.de - your verification links is http://https:/www.nrw-carcoding.de
there are missing one / and the url crashed.
http://https//www.nrw-carcoding.de?activation_key=xxxxxxxxxxxx&user_verification_action=email_verification&_wpnonce=742f1aed0c
Please do not disable other plugins without asking, its a live site!
Hi Nils,
Under Settings => General, Would you mind checking if you've added an extra slash(/) on address input?
Screenshot: https://ibb.co/M8h1v7r
Also, please try to remove (www.) or any third-party redirection plugin.