Send Autel a log file. There is a video on how to do this on your tablet (you must have your WiFi on). By the way, you must have your WiFi on when programming Mercedes in most cases. You should have a one year subscription included when you purchased your Jbox. I have heard that not all Mercedes files are included however.
If you are getting updates, your subscription is current. I read on IATN a year or so a go that Mercedes USA has not issued any J2534 licenses in the US. I went to thier website and found they want $1000 for a 1 year subscription. They don't sell 1 day subscriptions.
You have to fill out an application and they have to approve your license which is where things get jambed up. They don't approve (from what I read a while back), unless something has changed.
Please keep us posted so we can learn from your experience. I work on Mercedes and would like to know.
Kevin