A file restored from Time Machine that will not open

When a file restored from Time Machine will not open, the backup usually copied it faithfully in a state that was already broken. Time Machine keeps many versions of the same file, so the first move is not to repair anything: step further back, find a version that previews properly, and restore that one beside the current file. Only when every version is bad is it time to repair a copy.

Why a backup can hold a broken file

Time Machine copies what is on the disk at the moment it runs. It does not check whether a document is healthy, so a few ordinary situations produce a backup that will not open.

• The file was already damaged. A crash while saving, a bad download or a copy that was cut short all leave a broken file, and every backup made afterward holds that broken file too.
• An app was writing to it at that moment. A long video export or a large document being saved can be caught halfway, and the halfway state is what got backed up.
• The backup drive is failing. A disk with bad areas can hand back damaged data for files that were fine when they were written.
• Only part of something was restored. Some items, such as a Photos library or an RTFD document, look like one file in Finder but are folders inside. Restoring a single piece from inside one gives an app only part of what it needs.

The first two are about the file, and an older version usually solves them. The third is about the drive, and that changes what to do next.

Find a version that works before you restore anything

Apple describes the schedule this way: hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for all previous months, until the backup disk fills and the oldest are removed. For a file that has existed a while, that can mean many separate copies to choose from.

1. In Finder, open the folder the file lives in.
2. Open Time Machine from the Applications folder, or choose Browse Time Machine Backups from the Time Machine icon if you show it in the menu bar.
3. Use the timeline along the right edge, or the arrows, to step back in time.
4. Select the file and press the Space bar. Quick Look shows the contents straight from the backup, so you can check a version without restoring it.
5. Keep stepping back until a version previews properly. In list view, the size column helps too: a sudden drop in size often marks the point the file went wrong.

Quick Look can only preview what macOS understands: video, PDFs, images and most documents. For anything else, restore a likely candidate and test it in its app.

Restore without overwriting what you have

With the good version selected, click Restore. If a file with the same name is still in the folder, macOS asks what to do. Choose Keep Both. The current file and the restored one end up side by side, and nothing is lost if you picked the wrong version.

Then check the restored copy properly:

• Open it in the app it belongs to, not just in Quick Look, which can show a preview even when the full file has problems.
• Compare its size with what Time Machine showed. A restored file much smaller than the version you picked was not copied in full, which points at the backup drive.

Other places a good copy may be

Time Machine is not the only history a Mac keeps.

• Versions. Apps such as TextEdit, Pages, Numbers, Keynote and Preview save their own version history on the Mac. Open the document and choose File, Revert To, Browse All Versions. This history lives with the file, separately from the backup disk.
• iCloud Drive. If the file was in iCloud Drive and has since been deleted, check Recently Deleted on iCloud.com.
• The sender. For anything that arrived by email or download, the original message or link is often a clean copy.

When the backup drive is the problem

If every version fails, and other files from the same backup fail as well, test the drive. Open Disk Utility, select the backup disk, and click First Aid. It checks and repairs the file system, the structure that records where each file lives on the disk. It does not rebuild the contents of a file that was written badly. If First Aid reports problems it cannot fix, copy off what you need and start a fresh backup on a different disk.

Repairing a copy when no good version exists

When every version is broken because the file was damaged before the first backup, repair is what is left. Work on the restored copy, never inside the backup.

Manatee has a Repair mode for corrupt video, PDF and Word documents. Drop the restored file onto its menu bar icon or into its window, or right-click it in Finder and choose Services, Fix with Manatee. It reports one of three outcomes: Fixed, Partial (for example 34 of 41 pages, or the first eleven minutes of a video), or Not fixable. It always writes a new copy beside the file and never modifies the original, so trying costs nothing. It runs entirely on the Mac with nothing uploaded, which matters for files private enough to back up in the first place. Every feature is free for 24 hours, then it is $9 once.

Be clear about the limits. Manatee is not a recovery tool for deleted files, and it does not repair disks. Data that was never written, or was lost before the first backup ran, is gone, and no tool can bring it back. Partial recovery explained sets out what a partial result gives you, and why files get corrupted covers the causes in more depth.

Questions

Does restoring an old version delete the current one? Not if you choose Keep Both. Both files stay in the folder, one with a slightly changed name, and you can delete whichever turns out to be wrong.

Should I repair a file while it is still on the backup disk? No. Restore it or copy it out first. A backup is safest left exactly as it is, and a repaired copy belongs on your normal disk.

Why does the backup still show a file I deleted months ago? Older backups keep files as they were at the time, including ones deleted since. They stay until the backup disk runs out of space and Time Machine removes the oldest backups.