Ok so have had BB since last fall, have enjoyed it. Opted into beta earlier to test ui and now that the beta material is mainstreamed i cant opt out of the beta in the steam client and seem stuck in not being able to start the game since the main update. Kinda frustrated.
If you have “PlaysTV” installed and running, close it before running Battle Brothers. It comes packaged with some video drivers if you don’t uncheck some checkbox, so you may not even be aware that you have it.
If that doesn’t solve your issue, please please follow the instructions here.