JSONUtilities returning null

I am getting irritated at the JsonUtilities.FromJson(string data) thing. I pass it a working string and it just returns null causing everything to break. The problem is, it worked before and I didn't change anything. Here is the method that it's in:

 public void LoadData() {
         if( File.Exists(dataPath) ) {
             string jsonFileData = File.ReadAllText( dataPath );
             print( jsonFileData );
             if( jsonFileData.Equals( "" ) ) {
                 return;
             }
             Settings colorSettings = JsonUtility.FromJson<Settings>( jsonFileData );
             for(int i = 0; i < colorSettings.items.Length; i++ ) {
                 Color tempColor = new Color();
                 if( ColorUtility.TryParseHtmlString( colorSettings.items[i].value, out tempColor ) ) {
                     throw new System.Exception( "Unable to parse hex to color." );
                 }
                 colorPref.Add( colorSettings.items[i].key, tempColor );
             }
         }
     }

Any idea as to why it won't work anymore? Cuz I have no idea as to why it stopped working. I'm using Unity 5.6.