I don't have the 'Fenris UI' files but it sounds like it's installing out-of-date files into the
/Interface/FrameXML folder. Check the .zip (or whatever it is) and see if it does.
If it does do that, then you'll need to either:
a) ensure you have an up-to-date Fenris UI compilation; or
b) poke the compilation author to update it to be 1.9 compatible.
And if it
is a FrameXML incompatibility, I'd suggest asking him (then beating him about the head with a stick, if required) to stop using AddOns that install FrameXML crap.
