Users who have had a [Myst Online] forum account prior to mid-July (2013) and have not been active since then may be experiencing a bug in which they will return and log into the Myst Online forums, but see that there are no posts/forums listed. This bug is caused by a side-effect of the forum update that occurred mid-July and altered some traits of specific users who may have been listed as "inactive".
The solution to this problem is incredibly easy; it merely requires me to add them to the "registered users" group on the forums. Forum administrators are the only ones who have the ability to do this. So if this problem is occurring to you or someone you know, please message me on the forums directly or email the Cyan webmaster(s) about the forum account in question. I check my forum messages frequently (at least once or twice a day), so chances are I will fix the issue within a couple days of the message being sent (this isn't guaranteed, but it is a rough approximation).
Obviously, if a user is unable to see the forums when they log in, they are unable to see this informational post, but they can see this post if they view the forums logged out (as a guest). I'm hoping that this post can reach anyone who may be having this issue, but if it doesn't and you receive information from someone else that they are having trouble with their account and don't know who to contact, please send them the information from this post and/or tell them to contact the Cyan Webmaster (if they unable to message on the forums).
I would recommend that they contact me first before emailing the Webmaster account, because I monitor the forums frequently and the issue will probably be taken care of much faster than it would otherwise. Also, if a forum post is made concerning this topic, please direct the person in need of help to this post, and tell them to contact me.
Thank you all for your patience, cooperation, and support!