If the System Extension is not pre-approved by MDM (recommended), you can manually approve System Extensions locally after you upgrade the OS.
- On an endpoint running macOS 11 Big Sur, install the sensor on the endpoint and then go to the General tab in the Security & Privacy pane in System Preferences.
- Authenticate as an administrator. Click the Allow button next to the System software from application es-loader was blocked from loading message.
- Click the Allow button in the es-loader Would Like to Filter Network Content window.
The installer will finish running and load.