HelpPlease help. Why does this pop up??

Hey guys i have a weird error and i've tryed everything. I deleted my old source so now im trying to make a new with a Club559 modified because its a pretty stable source!

I have this weird error everytime i rebuild my solution and i've been looking through all of the .cs and .xmls errors the Wserver and Server said but i just cant fix it.... :C Can anybody may help me with this?

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I think you have XML id's that are the same.