The PC version of Black Ops 2 has bugs, and Activision is well aware of it. The bugs remain in existence because the PC version of the game was undoubtedly pushed out the door to coincide with the release of the Xbox 360 and PlayStation 3 versions.
Activision says that they are aware of the following problems, and intend to fix them, but have decided in any case to post the bugs in case they might affect you as a player. Here's the list of bugs, via Activision:
- A crash may occur if no DLC is owned when joining on a player that is in the Nuketown 2025 lobby.
- Having both an on-board audio device and a PCI sound card enabled at the same time may result in a crash.
- A crash may occur if the user tries to run the game without an audio device installed.
- Changing resolution while livestreaming may result in a crash.
- When viewing a film as a party, users may get a crash if the party leader leaves while the film is buffering.
- Loading Movies might not play if a user unplugs a USB audio output device after the game has launched.
- Users may lose functionality after locking their PC while a loading movie is playing
A steam error may appear after selecting update when prompted with a “Game Settings Have Changed” message. Launching the game again will resolve this.
These bugs only exist on the PC version so you shouldn't encounter them if you're running the 360 or PS3 version of Black Ops 2. If you encounter any other bugs, you're encouraged to tell Activision and Treyarch about it through Twitter on their @pcdev account.