[V1.09]
I've encountered this problem in two seperate games now - one Ironman and one not. On loading an Alien Base mission the game would advance 3 jumps on the loading bar and then just hang there. To exit I'd have to ctrl-alt-del to task manager.
The first time this happened was a non ironman playthrough. I'm pretty sure it's only certain kinds of base that are causing the problem, as I raided other bases than the one that wouldn't load while it was still on the map. Having tried verifying the cache and redownloading whole game to no success, I then deleted the /maps asset folder and reverified the cache. This seemed to work, allowing me to play the offending base.
Eventually I quit that game and started an ironman game, and on my first alien base the same crash happened. Deleting the /maps folder didn't work. I've subsequently tried moving the game folder to the c: drive (steam is on a partition), and replacing the tiles directory as per Section 6 of this thread http://www.goldhawkinteractive.com/forums/showthread.php/11735-Common-Bugs-Fixes-in-Xenonauts!. No luck there.
Anyone else have this issue? Am I, as well as humanity, doomed?