"Why not dogfood your own support subscription program and show us that it works."  

good point.

 6 months of seeing this screen is laughable:

Add/Edit Post

Since you posted to a moderated forum, a forum administrator must approve your post before it will become visible. Please be patient, this may take anywhere from a few minutes to many hours. Note that you will receive an email when your post is approved

As for the poster who said "one bug" overshadowed this [forum] whole undertaking, that, too, is laughable. Have you seen the number of people who can't post, the number of problems with displaying posts, subscription problems, listing problems, email problems, convaluted permissions, etc, etc, etc.  I could go on all night, but I have in enough posts and the problems still remain. I wonder how many people gave up like I did.

While I appreciate not being the one to take the blame, it is ultimately my fault since I am the only one who works on the module. I am not involved w/ the support service at all, but it is to my understanding it is not supporting usage on the website.

That said, I just purposely recreated the issue on here to explain how to fix it.

1. Checked the "Email Me When This Thread Has New Replies" checkbox towards the bottom.
2. Clicked the "New Thread"
3. Seen Error "Add/Edit Post is currently unavailable"

Now, to correct it (which just worked for me)

1. Clicked "My Settings"
2. Expanded the Tracking/Subscriptions area
3. Selected the forum where i was not able to post (Chat About It) - ie. i subscribed to it.
4. Saved My Changes
5. Went to this same post, clicked "New Thread" and all is well.

You would have to do this, as a work around, for all forums where you cannot add a new thread. Once you save a subscription and decide you don't want it, just update your profile and remove the one previously checked. In the background, each time a forum is subscribed to via my settings, it clears out all thread level subscriptions (which is where the problem is).

My advice, don't subscribe to notifications at the thread level or you will have to repeat the steps each time until the new version is pushed.