I have the exact same set up as the original poster but I only have 8GB of RAM (The recommended amount on the Steam Store page for RB6:Seige is 8GB so it shouldnt make a difference). This is all in a HP 8560w Elitebook...Yes the model with the i5 2520m and the Radeon FirePro m5950.
Heres the problem...
When I originally downloaded the game and installed it everything was fine. I attempted to open the game only to have it crash shortly there after, without anything popping up. I tried several solutions such as verifying the game cache, running the game in safe mode, setting the resolution to 800x600 via the launch options, reinstalling and updating all my graphics drivers, and renaming the Programx86 file, "deleting" the local content via steam (it doesnt actually delete it since it was renamed, obviously), then changing the file name back to its original and letting steam rediscover the files instead of reinstalling it.
That last solution worked once, and I played the game for about 2 hours (multiple sessions, i closed and reopened the game multiple times), without any issues. (played in 1280x720 at 60hz with perfectly playable FPS). But when I went to play it again today it did encountered the same error that occurred when I first tried to play it. Ive tried all the above fixes multiple times since then with no success.
If anyone has encountered this issue and found a fix for it please let me know. If you think I should start a separate thread for this, I am perfectly willing to do so.
Thanks for any help in advance.