I have the same problem: No posts possible, no conversations.
Funny you could open a thread here.
I have sent a report to the admins - waiting for a reply.
Seems like the site may be back again. I was able to create a new conversation.
So it may have been a chance coincidence that we could post here but not in other sub-fora.
I noticed that no posts where made the past days.
I also noticed that new registrations where possible (including some spammers, wich I already removed).