this is the output of the log (/home/USER/.steam/steam/SteamApps/common/MountBlade Warband/rgl_log.txt):
Starting new log file.
Version: 1.158
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very explanatory...
every other game I run works just fine, but when I try and run M&B Warband - the window shows up then turns grey after 5 seconds.
It doesn't completely crash, it just sits there. I've left it running like that for about an hour yesterday; didn't do anything, just a sad greyed window.
Some other games I have do the exact same thing at startup but they actually start running after 15-20 seconds
I use AMD's proprietary driver 14.2 (generated distribution specific driver), it's the most stable on my system so far and I've tried many different open source drivers - none come close to the performance I get with this driver set.
PLEASE FIX THIS - I LOVE THIS GAME - THIS WILL BE THE ONLY GAME I PLAY UNTIL BANNERLORD
EDIT: If it's not completely obvious already, I am running the beta linux client - no WINE
Ubuntu 14.04 xfce (no unity crap here)
AMD FX-8150 @ 4.5 Ghz
12GB RAM @ 2133
Radeon HD 7850 2GB
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Edit #2:
turns out it was steam's fault
https://github.com/ValveSoftware/steam-for-linux/issues/3280
anyone who is still having problems running the game - all you have to do is rename the file 'libgcc_s.so.1'
for me this was in the dir - '/home/USER/.steam/ubuntu12_32/steam-runtime/i386/lib/i386-linux-gnu/'
have fun with this awesome game!