I experience the same issue. All I could see as well was some sort of Bus error.
Also on 2.6 IMG on the Pi 2. Saving appears to work fine – I don’t see any message about it ingame, but I see the files that are created (in my case on a mounted NFS share so I can continue to play in another room on another device).

I was thinking about permissions of the savestates…but they are fine imo.