Add the Black Ops II folder as an in your antivirus settings to prevent it from happening again. 3. Verify Integrity of Game Files (Steam) If you are using the official Steam version: Open your Steam Library . Right-click on Call of Duty: Black Ops II . Select Properties > Installed Files .
The more insidious cause is the "silent deletion." Anti-Virus software (AV) operates using heuristics—patterns of behavior that look suspicious.
Click Verify integrity of game files... and wait for the process to complete.