Android Parceler Library - java.lang.RuntimeException: Parcel: unable to marshal value

Question

I am trying to use the Parceler library for Android.

http://parceler.org/

However I am getting the following error when trying to use it on a couple of my Java objects, this is the error I am getting:

java.lang.RuntimeException: Parcel: unable to marshal value

Here is the class that it seems to be failing on:

//MyObject.java
@Parcel
public class MyObject {

@SerializedName("name")
String displayName;

@SerializedName("address")
String displayAddress;

@SerializedName("css")
MyTheme theme;

@SerializedName("myList")
ArrayList<String> myList;

MyDetails myDetails;

// empty constructor needed by the Parceler library
public MyObject(){

}

//Various Getters and Setters, some manipulate data

Here is the MyTheme class:

@Parcel
public class MyTheme {

    @SerializedName("backgroundColor")
    String backgroundColor;

    @SerializedName("textColor")
    String textColor;

    // empty constructor needed by the Parceler library
    public MyTheme(){

    }

    //Various getters and setters and some non getter/setter methods

And here is the MyDetails class:

@Parcel
public class MyDetails {
    @SerializedName("description")

    @SerializedName("addressTypes")
    ArrayList<String> addressTypes;

    // empty constructor needed by the Parceler library
    public MyDetails(){

    }

    //Various getter methods

Finally I use the the MyObject Object in two ways, one where I send an ArrayList of MyObjects and again where I send a single one, as follows:

//ArrayList
ArrayList<MyObject> myObjects = ...
intent.putExtra(INTENT_EXTRA_OBJECTS, Parcels.wrap(myObjects));

//Retrieving
merchants = Parcels.unwrap(getIntent().getParcelableExtra(INTENT_EXTRA_OBJECTS));

//Single Object
MyObject myObject = ...;
args.putParcelable(ARG_OBJECT, Parcels.wrap(myObject));

//Retrieving
myObject = Parcels.unwrap(getArguments().getParcelable(ARG_OBJECT));

The error is very ambiguous and I am not sure how to debug it or find a solution, can anyone point to where the issue might be in my code?