So I went in to an nether portal when an zombie was following me. As soon as I reached the nether, when I was standing in the portal, the zombie went also in the portal since he was following me.
Then I got killed while standing in the nether portal. I tried to re-open the world, but it crashed.
Then I reconnected I got back on the place where i died, alive and well.
Bugreport is in the attachement.