I have installed the necessary PHP Pear modules for Horde to install, however when I go to install the script for Horde I receive the following error message.
Here is a screen shot of the modules showing installed and stable:
According to that screen shot Horde installed and is operational. That link is where you access it. The error was of no consequence according to what that screen shot says.
Something else I notice: your site bounces back and forth between secured and insecure. Your first link is not secure. I have to manually enter https to get it to a secure side but once I click something else it goes back to unsecured site.
Not sure that would have anything to do with it or not, but it is a bit odd.
Yes it seems the customer never enabled force SSL with their WordPress site. But now they want the Kronolith calendar installed. Unfortunately installing it via the Scripts page isnt going so well.
I will read the documentation and attempt to install it manually and let you know how it goes.