Hi,
i have my latest working saves from 22/04/2016. They weight approx. 1.8MB.
But since than & after GOG updates - game saves are not working. They have 32B size and are not visible in LOAD GAME screen.

I'm using Mac version of the game & GOG Galaxy 1.1.9 (beta).

Can you help me? Should I provide more info?
Thanks for your support!

I'll start by saying I know little of Mac's & nothing of GOG Galaxy, but save files with nothing in them is often caused by not enough free space on the hard drive that contains your temp folder.
So I would check to see how much free space you have on the hard drive your temp folder is on.
Mac's empty their temp folders on reboot, so if you don't reboot often you could try that.
They also keep multiple trash bins for each user, you could empty those to free up more space.

I have plenty of space (more than 120GB).

But I did (just a minute ago) fixed it:
* I reinstalled the game
* I repaired disk permissions

One of those helped :)