In summary...
Ensure your copy of Trainz /T:ANE is registered properly. Once registered correctly, your Trainz version(s) will appear on the timeline next to your name.
If you have already registered and still have problems, contact the Helpdesk via the link above to assist you with the process.
If you have registered under a previous username, contact the helpdesk and have them merge the two accounts together as that will ensure that all previous Trainz versions will be listed on the timeline.
Once registered, you will have access to the sub-forums.
John