Via [url=https://store.steampowered.com/news/244323/]the Steam store[/url]:

[quote=Valve]- Fixed HUD scope animation exploit (GitHub fix from mastercoms)
- Fixed case where the door model for Match Status HUD wasn't initialized before setting the submodel (GitHub fix from rabscootle)
- Fixed money not automatically being collected in Mann vs. Machine respawn rooms (GitHub fix from mastercoms)
- Fixed stuck Mann vs. Machine bots sometimes causing spawn softlocks (GitHub fix from Mentrillum)
- Fixed Mann vs. Machine ammo canteens not affecting energy weapons (GitHub fix from Mentrillum)
- Fixed 'Shell Extension' achiemevent not working for energy weapons (GitHub fix from Mentrillum)
- Fixed not being able to deploy parachute after landing and becoming airborne without jump button (GitHub fix from FlaminSarge)
- Fixed some heap allocated KeyValues leaks (GitHub fix from Dmitry Tsarevich)
- [b]Relaxed in-game chat restrictions for certain accounts[/b][/quote]

Rumor has it:

- Size is close to 50 MB