Zoom recording repair
Zoom recording repair: what it usually means
Zoom-style recordings can fail if conversion is interrupted, the app crashes, the Mac sleeps, or storage fills during save. The file may be a local MP4 that will not open normally.
If the file has real size, there may still be recoverable frames and audio inside. The safest first move is to leave the original untouched and create a separate repaired preview.
Do not trim, re-export, repeatedly convert, or overwrite the damaged file. If you need to experiment, work from a copy and keep the original exactly as it is.