Radarr is not compatible with OSX versions < 10.15 (Catalina) due to .NET incompatibilities.
codesign --force --deep -s - /Applications/Radarr.app && xattr -rd com.apple.quarantine /Applications/Radarr.appopen /Applications/Radarr.appRadarr uses a bundled version of ffprobe for media file analysis and does not require ffprobe or ffmpeg to be installed on the system. If Radarr says Ffprobe is not found this can typically be fixed with a reinstall.