Microsoft Teams second instance has no camera or microphone on Mac
Based on the current product workflow, the linked official documentation, and repeatable checks. Account and compatibility results must be verified on your installed versions.
Diagnose a Microsoft Teams second instance that can chat but has no camera, microphone, screen sharing, or call audio on Mac.
Confirm that the problem is limited to the second entry
Start a harmless test call in the official Microsoft Teams app and then in the second instance. Record microphone input, camera preview, speaker output, and screen sharing separately. If both fail, troubleshoot the Mac device or provider. If only the second entry fails, compare its permissions and application identity.
Check macOS privacy permissions
- Open System Settings → Privacy & Security.
- Review Microphone, Camera, and Screen & System Audio Recording.
- Look for both Microsoft Teams entries or the name macOS assigns to the instance.
- Enable only the permissions required for the role.
- Quit the affected entry completely and reopen it before retesting.
Check the selected devices inside the call
In Microsoft Teams's call settings, choose the intended microphone, camera, and output device. Disconnect virtual audio drivers, docks, or headsets temporarily if the wrong device is selected. A banner without sound and a call with no microphone are different paths; diagnose them separately.
Test one media function at a time
First verify microphone level, then camera preview, then speaker audio, and finally screen sharing. Record the first failing step and any macOS prompt. Recreating the instance before collecting this sequence makes it impossible to tell whether a permission prompt, device route, or provider restriction caused the failure.
Use the official app for a critical call
If the second instance does not appear separately in privacy settings or permissions revert after relaunch, keep meetings and calls in the official Microsoft Teams entry. Use the secondary instance only for capabilities that passed testing. A text message test cannot establish media compatibility.
The pass condition
After quitting and reopening, the intended devices must still be selected, the other account must remain identifiable, and a test call must work after a Mac restart. Dual App Master cannot grant camera or microphone access on the user's behalf; macOS permission and Microsoft Teams's own media implementation decide the result.