Have you recently seen the message “The file ‘%@’ could not be backed up” after Time Machine warned you of a failure? You’re not alone: many people who have installed the macOS 12 Monterey Public Beta have also received the same error. There’s no fix for it; it’s likely an error in how Time Machine scans for files.
This may mean your files are not properly being back up, however. I entered Time Machine on a Mac that’s running this public beta and looked around through older backups even where Time Machine claims it hasn’t been updated. The files all appear to be there, but I can’t check comprehensively.
If you’re concerned about losing data during this test period before Apple squashes this bug in a future beta or production release of Monterey, make sure all your document files are stored on a syncing service, like iCloud Drive or Dropbox, or syncing through iCloud services. It might be a good time to make nightly clones of your computer with Carbon Copy Cloner and enable in Carbon Copy Cloner > Preferences > Updates the option “Inform me of beta releases.”
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Author: Glenn Fleishman, Senior Contributor
Glenn Fleishman’s most recent books include Take Control of iOS and iPadOS Privacy and Security, Take Control of Calendar and Reminders, and Take Control of Securing Your Mac. In his spare time, he writes about printing and type history. He’s a senior contributor to Macworld, where he writes Mac 911.