CoreUI is no longer supported by the original author, but a few people are currently keeping it updated with game changes. Make sure you are getting it from here:
http://vginterface.com/downloads...eUI31.7.1.html
Then you'll need some patches that others have done for it:
This fixes the main inventory to have 50 slots:
http://vginterface.com/downloads/info185.html
This updates the character window to show resistances:
http://vginterface.com/downloads/info175.html