Problem Loading Plugins`

Hello.

http://howto.provamark.com/glossary/

Can you please check the plugin in the upper link. I don’t know what happened, but it is showing HTML code inside the content.

This belongs to one of my client, he already purchased the premium version.
I have tried both version premium or regular but problem is same for me
don’t know why ?

Please help me as soon as possible

Thanks

The page I need help with: [log in to see the link]