This error is notorious because it provides no context. It doesn't tell you which DLL is missing or why the load failed. Fortunately, this is almost always a redistribution package issue. Here is a breakdown of why this happens and how to fix it so you can get back to the front lines.
A new message printed in the air, crisp and human: Thank you. The game exhaled.
Permissions can sometimes block the game from "calling" additional DLLs. Right-click the BlackOps3.exe file in your installation directory. Properties Compatibility Check the box for Run this program as an administrator Disable Overlays and Background Tools