This is the technical root cause. Because the Redacted client modifies core game functionality, Windows requires elevated privileges to run it properly. If the client doesn't have the necessary permissions, the OpenNet plugin will be blocked, resulting in the error.
While the plugin is designed for efficiency, sometimes the message indicates a failure in configuration, or the plugin may fail to load entirely.
Below is a draft review and summary of its current state in 2026. Review: Call of Duty: Black Ops II – OpenNet Plugin
This phrase likely appears in a server or game console log related to Call of Duty: Black Ops II (multiplayer server or dedis) when server-side networking modules initialize.