Problem solved, for real!
I too was having the problem of the daily recurring error 3002. Many of the "solutions" posted here and elsewhere would solve the error and allow MJ to work, but only temporarily. In desperation I went to MJ website and initiated a text tech-help chat
to ask if they had a protocol they could email me. The tech helper said they had such a protocol, but could not email mail it to me. Before I had a chance to become argumentative, the helper began the help chat session, so I just went with it. Now, over
two weeks later, my MJ has been working rock-solid stable, with no errors.
The helper asked me for information. First, I had to make a LAN connection to my modem/router (Zoom 5352) and access it. I knew how to do this, but the helper had the information, should I have needed it. From the router pages, the helper asked me for
the MJ's IP address, the IPv4 address, and the default gateway; presumably the helper entered this information at his end. Then the helper guided me through port forwarding: IPv4 only, 5060 only, both protocols, enable. Ta da - done! The help chat session
lasted about 20 minutes.
Now I'm a happy customer. I hope someone may find this post helpful.