I wonder if it's similar to the error that some of us started seeing in the logs for our Fibaro Dimmer 2, using a custom driver. Our error is not exactly the same, but also mentions a null object while trying to parse. It's mentioned in this post:
The line reference in the error message:
def cmd = zwave.parse(description, [0x20: 1, 0x84: 1, 0x98: 1, 0x56: 1, 0x60: 3])
