A number of users have reported a crash error while the game is loading with a message 'Could not lock vertex buffer: Err 80004005'. We've haven't encountered this in our internal testing and so it appears to be related to certain hardware configurations. For now I can only suggest updating DirectX or your video drivers. We're looking into this now and will hopefully have a solution shortly. I'll post again when we know more. Thanks for your patience.

I'm not sure if this will help, but I've updated the steam build so that it now installs the applicable libraries (VC 2013 & DirectX) when the game starts. For those who want to try this out, you may need to quit steam and re-open it in order to force Rome to update.

Thanks for trying. The DirectX thing was a bit of a long shot, but worth a try. At the moment our best guess is that it's an nVidia vs ATI issue. Most people who are experiencing the problem are running some version of an nVidia GTX card where as it seems to be working for those with Radeon cards. Here in the office we have mostly Radeons with one older nVidia card that hasn't had any issues.

Thanks for your patience, I'll post again as soon as I know more.

Progress! I just picked up a new nVidia GTX 650 ti card and was able to duplicate the crash. I haven't tracked down the cause yet, but things should go much faster now that I can replicate the problem.

The other good news is that, at least on my machine, the game does still work in windowed mode. Since you can't get to the options screen, you'll need to alter the settings file directly. The file is located in your "user/app data/roaming/Longbow Digital Arts/Hegemony Rome" folder. Open the 'settings.xml' file in a text editor and change the line that says "<windowed>false</windowed>" to read "<windowed>true</windowed>". You might also want to adjust the resolution from "0,0" which is desktop res to something less than your desktop so it doesn't get clipped.

Let me know if you have any questions.

Update: I've found a solution that fixes the crash in fullscreen, but I'm still not clear why it was crashing in the first place and I don't know if the fix has any side effects. We're going to do a little more testing, but we should have an update with a proper fix early next week.