Movavi Screen Recorder uses a tool called Audio Capture Engine (ACE) for system sound recording on MacOS. Usually it's installed automatically along with Screen Recorder. If for some reason you need to install it manually, please follow this article.


0. First of all, launch Screen Recorder, go to its main menu and select "Install Audio Capture Engine (ACE)" option:


Then you will need to give additional permissions for the utility:
 
1. Go to the General tab of the Security & Privacy settings.
2. Click the lock to make changes and enter your user password.
3. Click the Enable system extensions… button to proceed.
 
 
 
 




























Steps 4-16 are only relevant for Mac systems with M1/M2 chips.




4. This dialog explains how to access the Mac's “Recovery” environment. Click Shutdown.



























5. To boot to the Mac's “Recovery” environment, press and hold the Touch ID or power button on your Mac. When the screen says “Loading startup options…”, you can let go.
6. Select a user with administrator privileges, then click Next.



























7. Enter your login password, then click Continue.
8. The Startup Security Utility should now load automatically. It can also be accessed from the Utilities menu.
Click your main system drive to highlight it, then click the Security Policy… button. This will enable you to adjust the security policy so system extensions like ACE can run.

9. Switch to Reduced Security.
The “Reduced Security” setting still provides your Mac with powerful security, only allowing operating systems approved by Apple to run.
 
10. Enable the first checkbox, “Allow user management of kernel extensions from identified developers” and click the OK button.
Despite the name of this setting, ACE is not a kernel extension. Instead, it's a standard audio plug-in, which receives enhanced privileges to access your system's audio. MacOS 11 simply uses the kernel extension verification system to allow ACE to load as well.
11. Enter your password, then click the OK button. The new security policy will then be applied. When it's finished, the window will close.
 
12. You can now click the Apple () menu in the upper left. Select Restart, then log back into your account as normal.
13. You'll now see a message from the system, stating that ACE has been blocked from running. Click the Open Security Preferences button to proceed.
If you accidentally clicked Ignore, select System Preferences from the Apple () menu in the upper left. Click Security & Privacy, then the General tab.
14. Click the lock to make changes.
15. Click the Allow button to permit ACE to run on your Mac.
16. You're at the final step. Click Restart. When you log back in to your Mac, the application will be ready to go. Good work!