HRESULT: 0x80131018 Error..
I resolve my issue, in GAC folder with explorer i could see the system.runtime.serialization dll but when i used cmd prompt on this folder the dll exist on GAC_MSIL and not on GAC. So i have copied System.Runtime.Serialization folder from GAV_MSIL on GAC and after reboot VS my project compile perfectly. To move dll easly i used start > run > cmd type : "cd\windows\assembly" type: "attrib -r -h -s desktop.ini" type: "ren desktop.ini desktop.bak" now i can open the GAC folder normally in your explorer, and you can see the actual structure.