oh ok, ah goobalie gook,(as my 7yr say's cause he can't curse). this might be that you had an updated homebrew(can't remember what version it is). but when 4.3 came out. you could keep homebrew,but all the cios/ios would end up getting stubbed. so you'll have homebrew, but nothing would work.(this is what happened to me when i first started with modding, an didn't know any thing about priloader,or cios stubs an so on.). i know how others feel. about what i'm going to say.
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the way i fixed mine an got every thing working after my little problem. was do a system format. offline, an if you do have priiloader, uninstall it. or turn it off if you have any of the block features active.(block updates on disk or online). though you'll still be on system menu 4.3 after update. you can rehack using letterbomb.( i used smash stack) but this would only be an xstream case. please make sure you follow an try xflax's way first. try mine as a last resort.
hope you get things running again.