Take a look at this screen : http://img15.hostingpics.net/pics/536295wtf.jpg
As you can see all the stats and skills are gone, but what's worse is that I cannot place any unit anymore. A bug from the latest update most likely, as it never happened to me before. It only seem to affect Extreme rank battles, I can still play in lower ranks.

This bug is caused in an old build of the game when you have the "Anonymous Book" equipped.

You can solve the bug temporarily by not using that book. It is definitely fixed in the latest version I have sent to GOG, 1.1.00. That's the game version, I think GOG has a different installer version. You can check the version # on the title screen of the game, bottom right-hand corner. If it's not 1.1.00, go to the GOG game page and get the latest update. There's been a couple in quick succession in the last few weeks.

Yup, looks like I did miss the patch. Thanks for the fast reply!