[Eikinskjaldi]

Error 12 means the OS was unable to allocate enough memory. What OS are you running, which storage engine are you using, what kind of plan are you on (shared, vps, dedicated).

I think it likely that your posts are gone, but it could instead be a really, really corrupted index file. The best way to check is to look at the file directly. Assuming you are on some kind of vanilla linux and have root access, as root type ls -l /var/lib/mysql/<your db name>/vb_post.*

If you don't have root access or are not using myisam, this will not work.