Dr. Bad

Try bandaging yourself. That solved this problem for me.

When it happened to me, I had previously logged out with full health, no broken limbs, not in shock, not being shot at, and there weren't even any zombies around to have aggro. On a whim, I logged in to see what else I could do despite being "dead." The Map worked fine, switching clothes (from camo to ghillie) just made my character swap skins then fall over. When I bandaged myself, however, I magically sprung back to my feet. I don't even think it consumed the bandage. It sounds like, on top of the new annoying death issue, you got the old death on login issue too, where you lose all items, including your backpack. If you happen to have a bandage, try using that to see if you are revived as well.

The same thing just happened to me. I logged in to the server I had been playing on earlier in the day, and when I got into game the server message stating that I had died appeared. I also did not get the death screen after the countdown, but assumed it had something to do with lag (FPS not latency). I logged into a different server to start again, but I didn't get the character creation screen. Instead was back where I logged in and "died." Still had full health, was still able to eat and use items in my inventory, but I was immobile and sprawled out like a corpse.