As part of the transition from 32-bit to 64-bit technology in macOS, you might see an alert in Final Cut Pro or Motion about legacy media files that won't be compatible with macOS Catalina.

Before you upgrade to macOS Catalina, you can use Final Cut Pro to detect and convert all incompatible media files so they'll be compatible with future versions of macOS. After you upgrade to macOS Catalina, the option to convert the incompatible files will no longer be available.

To make sure any new media files you create are compatible with macOS Catalina, use cameras and media formats supported by Final Cut Pro, and use media formats supported by Motion.

When trying to play incompatible media in macOS Catalina, you might see an incompatible media message in the viewer if you haven't converted the media before upgrading to macOS Catalina.