System.ArgumentException(0x80070057): An item with the same key has already been added. at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) at IdavallWebb.BaseDAL.ListToParameters[T](List`1 list, String paramName, Dictionary`2& paramList) at Schema.Page_Load(Object sender, EventArgs e)