Can't load/save 39 GC DLC (Piatek)

[Longasc]

I can't load/save in turn 20/20 of the Piatek scenario.

I already proceeded but kept this autosave.

You will have to take the final objective and then you will see...:

I could not save after turn 20 in the "view battlefield" screen.
Right now I try to reproduce this, but I am STUCK and the game doesn't even continue.
The AI doesn't complete its turn for some reason.

http://www.filedropper.com/piatek

Here's my link to the save (zipped autosave)