Civ has suddenly stopped working after 250+ hrs of gameplay

Hello, I've posted this on the Steam forums but I'm guessing this is a much more active community for Civ so I'll post it here as well:

"Hey everyone, I'm really not sure what's going on but my Civ doesn't want to start. At all. A couple of days ago after I started Civ and clicked the usual "DirectX 10 & 11 (Recommended)" in the launcher, the launcher stayed there but Civ never started. I didn't know what was going on but I tired of waiting about an hour after that so I exited Steam and rebooted the PC. I tried to start Civ again to no avail. I've uninstalled and reinstalled. Nothing. I click "Play" and after the launcher closes, that's it, Civ never ever starts. I don't even see it in my Task Manager? I'm completely clueless as of why it's not working, I was playing it fine a week ago, and I've no idea how to fix it. Any help would be much appreciated!"

Additionally, I've deleted my game cache and verified game cache but Civ is still not starting. I mean, I played the game for 250+ hours before so I don't really know why I'm not able to play it all of a sudden. Again, any help is much appreciated.

same problem here. Must be something with the new Steam patch.

Oh.. That hadn't occurred to me!
I've been trying to figure it out with a guy on the Steam forums. I've checked everything: drivers, reinstalled DirectX and vcredist, game cache...
It did launch briefly and I started a new LP (because I'd deleted Civ's folder under My Documents and didn't back up my saves) but, as I was about to settle my first city (other than my cap), I wanted to install EUI so I quit to Windows. After installing it, the game wouldn't launch. Since, I've deleted the UI_bc1 folder, verified game cache again but the game just won't launch. I hope you're right!

I don't play on Steam, I downloaded from the Apple store, but I'm having the same problem. After hundreds of hours of gameplay both Civ5 and Beyond Earth now will not load at all. What's happening?

This could be happening because of a new update for Civ V? (Yeah, like they would continue updates still) But, I suggest trying later on or at a later time and it should work. Or try reinstalling it (You obviously did that), restart computer, or just wait and see how that works out.

@Levine--My App Store version didn't want to launch last night. First time it happened. Then I got a message the file was corrupted and to redownload from the App Store. So I go to the App Store and I can't restore my purchase of it (plus all the packs).

So I trashed the game from my applications folder. And--thankfully--I do a weekly clone of my system. So I dragged the game from the application folder on my 2nd drive to my first--and thought that would work. It didn't. So I then launched the game from the second drive and it worked. And I quit it.

I then relaunched from my first drive and everything is fine now. Very weird.