Here is a save game where I couldn't end the current turn. However, reloading does allow me to end the current turn. BUT, if you end turn, auto run the magnar attack, you will see the same behaviour again. Magnar has a huge stack of armies that keeps attacking me, but it doesn't load the combat screen. And I can no longer complete my turn once this happens
Here is the saved game:
https://dl.dropbox.com/u/100579257/tuf2.EleSav