I had the same prob with this addon. Copied the files and my site stopped loading. I didn't overwrite the index default file though.
The "site-killer" file is \includes\auto_loaders\overrides\config.core.php. The one in this mod has 10 fewer lines that the one in my cart. ???
I tried core in a couple other places, then finally deleted it. My site loads but no cloud display. page_4 doesn't show anything, and I tried it in an EZ page and that shows code, no cloud. I've put the code a couple places and no go yet.
Another odd thing: in the mod, the only file in \includes\templates\custom\template\ is tpl_index_default.php. The ONLY file.
Then, in the instructions, it says
** Important ** please make sure not to overwrite your \includes\templates\custom\template\tpl_index_default.php
So I didn't upload that file. But if we shouldn't overwrite why in the world is that file in there?
If I find something that works I'll let you know. I noticed some other had this mod working but no one has posted a link so we can see it. Even the developer doesn't have as much as a screenshot. This is a couple years old, maybe it's not compatible with 1.3.8a, or with the latest security patches.