Pre-August 2019 versions of Acrobat DC, Acrobat 2017, and Acrobat 2015 applications cannot be licensed on macOS 10.15 Catalina. Adobe recommends customers updating their Acrobat DC, Acrobat 2017, or Acrobat 2015 to the latest release. To update from within the application, on the Help menu, choose Check for updates and follow on-screen instructions to complete the update process.