What I wanted: Test Mkps3tsfile for a client video remux – supposed to take PS3 MKV remuxes with h.264/AC3 streams, repackage to clean TS containers for legacy hardware playback, strip unwanted subtitles/audio tracks, and fix timestamps without full reencode. Grabbed the DMG from an OrchardKit video tools page like Mkps3tsfile - OrchardKit (bookmarked that page because the format specs matched my weird PS3 rips when ffmpeg choked). Needed to process 4.2GB Avengers clip (trueHD passthru to AC3, burn PGS subs), output broadcast-ready TS for their old Sony deck. Mounted around 23:10, dragged to Applications.
Launch attempt one, 23:12. Dock bounce. File browser pane flickered – "Drag TS/MKV here" tooltip showed – vanished. Clean ghost. Right-click Open triggered Gatekeeper "can't verify developer." Clicked through. Drag target active for 0.7 seconds (file icon shadowed), PID 5821 terminated silent. No crash dialog. Restarted Dock. Same quick death. (Classic me – rebooted first. Wasted 3 minutes.)
Try two, 23:16. Trashed app, remount DMG, fresh drag. Launch at 23:17:04. Identical bounce-poof. ps aux | grep Mkps3tsfile zilch post-bounce. codesign -dv /Applications/Mkps3tsfile.app spat "unsigned binary, no entitlements." Figured bad DMG. MD5 perfect. 9 minutes circling.
Privacy Settings glance, 23:22. System Settings > Privacy & Security – no "Allow Anyway." Sequoia skips prompts for total blocks now. sudo spctl --master-disable warned "legacy, ineffective post-Monterey." Relaunch crashed: "dyld cache slide fail" under securityd. Re-enabled. Back to vanish. (Self-drag: tried Activity Monitor force-kill phantom. Empty.)
Live tail time, 23:28. log stream --predicate 'subsystem == "com.apple.securityd" OR process == "Mkps3tsfile"'. Launch confirmed quarantine ghost + AVFoundation deny. Smoking gun: "reject-unsigned-framework /Contents/Frameworks/TSRemux.dylib" and "runtime block: mediafoundation unsigned payload."
What worked, 23:32:15. xattr -r -d com.apple.quarantine /Applications/Mkps3tsfile.app. No stderr. Relaunch stuck – drag target live, dropped 4.2GB MKV. Stream analysis instant: h.264 Main@L4.1, AC3 640kbps, PGS subs track 2. But remux? "Cannot probe input container – permission denied on /private/var/folders media temp." TCC grabbing AVAsset staging.
System Settings > Privacy & Security > Full Disk Access. Unlocked padlock, "+" → Mkps3tsfile.app, green toggle. Screen & System Audio Recording too (mux preview capture). Quit fully (pkill -f Mkps3tsfile), relaunch required. Dropped MKV again – streams isolated clean, burned PGS to h.264 overlay, AC3 downmix 5.1→stereo option, TS output 4.1GB timestamp-perfect. ffmpeg verify: ffprobe output.ts confirmed MPEG-TS spec compliance, PTS/DTS monotonic.
Apple's Gatekeeper runtime guide nails unsigned media tools. Privacy controls overview covers AV mux temps. App Store video converters sandbox slow.
If starting over: xattr strip post-drag, Full Disk + Screen Recording before optimism. Script it: #!/bin/zsh; xattr -r -d com.apple.quarantine "$1"; open "$1". Total debug: 27 minutes. Legacy deck played flawless. Next video oddity, Terminal leads. Muscle memory update complete.