I don't have access to Catalina. I guess I would try making sure that all versions of the Apache Flex SDK Installer have been uninstalled. Then go to Adobe or Harman and get the latest version of AIR and install that first. Then try installing the Installer again. Some folks were complaining of this message recently: https://community.adobe.com/t5/air/air-runtime-installation-failed/td-p/10481129
You can also use Apache Ant to install the Apache Flex SDK. HTH -Alex On 12/19/19, 6:05 AM, "Wim Deblauwe" <wim.debla...@gmail.com> wrote: Hello, I just downloaded the latest Apache Flex SDK Installer from https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fflex.apache.org%2Finstaller.html&data=02%7C01%7Caharui%40adobe.com%7C0337b7cf579e4eac395908d7848c840b%7Cfa7b1b5a7b34438794aed2c178decee1%7C0%7C1%7C637123611358342901&sdata=ugzeXHR23nQ9W5hqv4wTIJJU2aVoYA4l7y5vbbIxhlM%3D&reserved=0 which is verion 3.3.2 at the time of writing. When I tried to install it on my macBook Pro using macOS Catalina 10.15.2, I get the following message: *This application requires an update to Adobe AIR that is not available for your system. Please view the system requirements <http://www.adobe.com/go/air_sysreqs/> for Adobe AIR and update your system accordingly.* The link opens http://www.adobe.com/go/air_sysreqs/ but that just redirects to https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.adobe.com%2F404.html&data=02%7C01%7Caharui%40adobe.com%7C0337b7cf579e4eac395908d7848c840b%7Cfa7b1b5a7b34438794aed2c178decee1%7C0%7C1%7C637123611358342901&sdata=v9nLXAzmGEW0Nw5PuXU1Ul0jPj2PHYYeIPaO%2BTpryO0%3D&reserved=0 immediately. How can I install the Flex SDK on my computer? regards, Wim