Included is a TacticalOps.sh file to start ut-bin using TacticalOps.ini as configuration file.
Modify section [Engine.Engine] in TacticalOps.ini and set the correct ViewportManager:
[Engine.Engine]
...
ViewportManager=SDLDrv.SDLClient
Some will also edit section [SDLDrv.SDLClient] to manually set the screen resolution:
[SDLDrv.SDLClient]
...
FullscreenViewportX=1024
FullscreenViewportY=768