The new Catalina OSX and Big Sure have a more restrictive “Gatekeeper” than before. To fix this, go into System Preferences > Security & Privacy > General. Make sure that under “Allow apps downloaded from” that it is set to “App store and identified developers.” Even then, “Gatekeeper” might block opening the app. If so, go back into Security & Privacy and you will see an additional message asking whether you want to open the blocked app anyway. Proceed to approve.

For more information, read the article, “Safely open apps on your Mac,” at https://support.apple.com/en-us/HT202491 and/or search for keywords Catalina / override / Gatekeeper on Google or another search engine.

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