My take here is that you loaded my "
Shadow d20" houserules data set which is cool. But then you downloaded the "
PFRPG_Sources.zip" and installed all of the
.1st files also.
Yea as you can see they don't work together as my "
Shadow d20" already has those sources so they clash together.
Simply remove the the .1st files that you added from the zip file.
Anyone is free to install and use my "
Shadow d20" data set. Just keep in mind I have a good number of changes to HL core rules that are for my home personal group. Also I may have new ones that show up in the future also with each new version. It does have lots of extra races, Runeforged (renamed warforged), catfolk, changelings (Eberron version), shifters, dragonborn, and Shadow Minotaurs. Which may interest others.
My advice would be to load it to its own pathfinder game folder. Something like "pathfinder_shadowd20".
Thanks