I redownloaded and reinstalled TeamViewer (without attempting any kind of uninstall), and the same thing still happens. I have BitDefender installed but Bitdefender Shield and Bitdefender VPN are both disabled. Then I rebooted again and got the same thing happening again.Īt some point I may have exited the Teamviewer app completely, and I'm thinking this may be the cause of it not working. I force-quit those instances and tried running the TeamViewer icon and got the same message. Previously, after the first reboot, it showed only one instance of TeamViewer and one instance of TeamViewer_service. Activity monitor shows two instances of TeamViewer and one instance of TeamViewer_service open. I click on the Teamviewer icon in the doc and get that message. The Teamviewer Icon is not in the menu bar like it usually is. That should restart TeamViewer and you should be able to access the TeamViewer window from menu bar icon or the Dock, as described above. Find the TeamViewer_Service process in the list, and quit it. From the menu bar choose View > All Processes. In case there is neither a (running) app icon in the Dock, nor a menu bar icon, please open Activity Monitor (Applications > Utilities). If you see either one of those, use them to open the TeamViewer window. In case you have 'Start TeamViewer with system' turned on and get this error when you attempt open the TeamViewer app from the Applications folder, TeamViewer is likely already running and the error message might be due to a change in macOS Big Sur behavior.Īs a quick workaround, here are some ways that you can use to open the TeamViewer window in that situation:Ĭheck for the TeamViewer icon in menu bar on the upper right corner of your screen, or check for a 'running app' icon (with a small dot below it) in the Dock.

When exactly are you getting that error? Is it in response to any specific action?

Teamviewer for mac not working