RuntimeException: Unmarshalling unknown type code 3145776 at offset 236

Question

I want to pass a parcelable object over to another activity. These objects contain a bitmap, and in some cases I get the error: RuntimeException: Unmarshalling unknown type code 3145776 at offset 236. Here is the code:

_profilePicture = (Bitmap) in.readValue(Bitmap.class.getClassLoader());

Weird thing is, that it doesn't happen with all objects like suggested in other StackOverflow answers. I pasted this piece of code somewhere in my proguard file (the one for optimization, not the "proguard-android.txt" one):

-keepclassmembers class * implements android.os.Parcelable {
    static ** CREATOR;
}

It doesn't work though.