Issues with Urban Dead addons

I absolutely love the mods that I found in this forum to add to Urban Dead, but they giving me error pop ups whenever I get on Urban Dead. D: Is there an easy way to figure out which mod is doing it, and why?

This is the message I keep getting:

GDF [Exception... "Component returned failure code: 0x8000ffff (NS_ERROR_UNEXPECTED) [nsIPrefBranch.getComplexValue]" nsresult: "0x8000ffff (NS_ERROR_UNEXPECTED)" location: "JS frame :: chrome://udwidget/content/colorizer.js :: getDataFile :: line 156" data: no]