Game suddenly started freezing up on me

[Korvessa]

I have had the game for several months now. I play on my laptop & haven't had any issues that I am aware of.
Last night after restarting my computer, it suddenly developed problems.
The last thing I did in the game was finish the Spanish Civil War DLC and saved it at the beginning of the 1939 DLC.

It loads up OK, but as soon as I hit the "load" button it freezes up. I don't even get the menu, it just stays on the main menu page. This has never happened before.
I tried to play a scenario - and that seemed to work OK, but as soon as I try and save or load a saved game, it freezes up.
It doesn't matter if I try through the menu or use the short-cut key - it still freezes up on me.