okay, before you try and attempt this again, make a backup of your feral heart folder!! make sure to place the copy in a safe place, so you won't have to uninstall everything again and you'll have all the original files at the ready.
nevertheless, the only reason i can think of why the mass markings & items isn't working is because you may not be installing them correctly, or a crucial file is being deleted in the process.
for your ease, here is how i installed mass markings & items on my computer (i use windows 7, so the locations of the folders will vary) as this worked for me.
mass markings
1. drag and drop all the contents from the 'textures' folder you downloaded into the pre-existing folder, found here: C:\FeralHeart\media\textures
2. drag and drop the markings.cfg file you downloaded into the main feral heart folder, found here (when prompted to replace the existing file, click 'yes'): C:\FeralHeart
items
1. drag and drop all of the items (including the textures, materials, meshes, etc.) you downloaded into this folder: C:\FeralHeart\media\items
2. drag and drop the items.cfg file you downloaded into the main feral heart folder, found here (when prompted to replace the existing file, click 'yes'): C:\FeralHeart
i hope this helped, if this didn't work then i'm not exactly sure what else is happening.