The pm inbox is currently broken. There is no link to check pms on the main page. However, it is still possible to send one by going into the receiver's profile.
mine works fine.
I suspect your having the zoom issue which affects the forum sometimes and occasionally makes links disappear, try either running the forum in full screen or changing the zoom level.
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)
That fixed it.
Amazing how many issues non-maximized windows cause.