Samuel,
I did set up your Private Messages on the fully functioning site.
Everything works.
However, I have to say that it took me a while to sort out the 404 error.
The problem is that my path to forums is not just /forums but xxx-forums.
I modified the path in your loader.php – at first I modified it in the child theme where I copied the entire plugin folder. It didn’t work – so I saved the form settings, permalinks etc – it didn’t work. So I modified the loader.php in in the parent plugin folder – saved the settings – it didn’t work. It started to work only after a while for no apparent reason.
Is there a time lag? Also, do I have to modify the loader.php in both the parent plugin and child theme folders>
Another thing: the option in the profile to email the user whenever somebody sends a message is not turned on by default.
In any case, I am relieved that the sending of messages works. Many thanks.