This is the only ErrorFilter of vanilla i believe, it does its job but you gotta add what it should filter on ur own (remember to write the errors the exact same way they pop up as, like with Capital letters or with . In the end etc)
http://wow.curseforge.com/addons/project-532//script UIErrorsFrame:Hide()
This macro works too but it only works untill the server restart/crash and then u gotta use it again hence why i recommend RogueSpam instead