Writing a XML file to iOS

I am trying to write to a XML on iOS, but it seems to be impossible. Tried several different this but none have worked.

I have read that iOS only have write access to it´s /Documents folder, so I have tried to set a Application.dataPath to the Documents folder. But I get this error in Xcode :

 DirectoryNotFoundException: Could not find a part of the path "/Users/mariusmathisen/Library/Application Support/iPhone       Simulator/7.1/Applications/6AE4AF70-EFDF-46F0-9947-5C0936F3AD27/DaXml.app/Data/Documents/gamexmldata.txt".

This is my code to write to XML :

 blic void WriteToXml()
     {
         Debug.Log ("Du nådde metoden");
         //string filepath = Application.dataPath + @"/Data/gamexmldata.xml";
 
         XmlDocument xmlDoc = new XmlDocument();
 
 
         GameControl.control.outputXml = "Du nådde WriteXML";
         if(File.Exists(Application.dataPath + "/Documents/gamexmldata.txt"))
         {
             Debug.Log("Filen Fantes");
             GameControl.control.outputXml = "DU ER I Writetoxml og filen fantes";
 
 
             
             xmlDoc.Load(Application.dataPath + "/Documents/gamexmldata.txt");
             //xmlDoc.Load(filepath);
             
             XmlElement elmRoot = xmlDoc.DocumentElement;
             
             // elmRoot.RemoveAll(); // remove all inside the transforms node.
             
             XmlElement elmNew = xmlDoc.CreateElement("rotation"); // create the rotation node.
             
             XmlElement rotation_X = xmlDoc.CreateElement("x"); // create the x node.
             rotation_X.InnerText = x; // apply to the node text the values of the variable.
             
             XmlElement rotation_Y = xmlDoc.CreateElement("y"); // create the y node.
             rotation_Y.InnerText = y; // apply to the node text the values of the variable.
             
             XmlElement rotation_Z = xmlDoc.CreateElement("z"); // create the z node.
             rotation_Z.InnerText = z; // apply to the node text the values of the variable.
             XmlElement navnElement = xmlDoc.CreateElement("name");
             navnElement.InnerText = navn;
 
             GameControl.control.inputXml = navnElement.InnerText;
 
             elmNew.AppendChild(rotation_X); // make the rotation node the parent.
             elmNew.AppendChild(rotation_Y); // make the rotation node the parent.
             elmNew.AppendChild(rotation_Z); // make the rotation node the parent.
             elmNew.AppendChild(navnElement);
             elmRoot.AppendChild(elmNew); // make the transform node the parent.
 
             xmlDoc.Save(Application.dataPath + "/Documents/gamexmldata.txt"); // save file.
             Debug.Log("Filen er lagret");
         }else{
 
             xmlDoc.Save(Application.dataPath + "/Documents/gamexmldata.txt");
         }
     }

Are there any suggestion to why I can´t get the XML to write to iOS and it´s folder? What am I doing wrong?