Signature Is Null

[cmcfatter]

I am trying to use the provided UI for the quickchip transactions and after I write a signature it is not being saved in the result. Because of this I have been trying to make the app with my own UI but that has had its own share of problems. If I could obtain this signature it would enable me to just use the provided UI instead.

Here is my code for retrieving the signature:
try {
byte[] decodedString = Base64.decode(result.getSignatureBase64().getBytes(), Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
} catch (Exception e) {
e.printStackTrace();
}

The error is java.lang.NullPointerException: Attempt to invoke virtual method 'byte[]java.lang.String.getBytes()' on a null object reference