Same here.
In detail:
Click play
Firewall posts "Do you want to allow this app to make changes..." = Yes.
Opens box: Performing first time set-up. Step 1 of 1.
Box disappears:
Play button shows CANCEL.
Play button shows STOP.
PLAY button becomes active again.
I have read several posts to try to resolve:
Re-installed in native steam directory (C:\Program files x86\steamapps\common\Mount & Blade II Bannerlord) - I usually install games to a different drive. NO EFFECT
Set all .exe files to run as administrator. NO EFFECT
Followed directions in this post:
https://forums.taleworlds.com/index.php?threads/game-failing-crashing-at-launch.397007/
: I am unable to install .NET v4.8.2 - My PC has .NET v4.7.0, and that is as high as it will go. Windows 10 has failed to install updates for some time - and after looking into this, I believe it would need a complete re-install to fix the issue - that is beyond me atm. I mention this because the crash reporting software packaged with the game requires .NET 4.7.2 or above (...\Mount & Blade II Bannerlord\bin\CrashUploader.Publish\CrashUploader.Publish.exe). I don't know if there is a connection, but the software won't run with my version of .NET. Note that I have no trouble with any other game on this PC, so my out of date Windows install isn't usually an issue. I'm probably not up for trying that big of a fix unless it starts impacting on all my games.
: My virus checker and firewall is set to allow Steam games. Created exceptions for Bannerlord specifically, and then tried turning both off. NO EFFECT.
: Deleted the language file referenced in the above link: NO EFFECT.
: Verified and reinstalled several times (including deleting all game references in other directories), with and without changes outlined above. NO EFFECT.
If I try to launch using the .exe files directly (...\Mount & Blade II Bannerlord\bin\Win64_Shipping_Client\...):
Bannerlord.exe: Nothing happens.
Bannerlord_BE.exe: "The exception unknown software exception (0xe0434352) occurred in the application at location 0x00007FFE669B9E08" - I believe this file has something to do with anti-cheat in multiplayer?
TaleWorlds.MountAndBlade.Launcher.exe: Nothing happens.
Bannerlord.Native.exe: White screen with a cursor for a while, the some kind of picture screen (as if the game were loading), then it just drops back to windows with the PLAY button active again.
That's all I know.
A lot of threads seem to be raising variations of this, but it's all a bit vague to-date.
I would like to play this game - it looks great on the YouTube play-through, and I enjoyed Warband.