If your Mac can't save files to an external drive — by Apple Support

intermediatepageLink only (©)

Covers what to check when a drive reads fine but will not accept new files. Looks at free space, drive format, ownership permissions and disk errors.

Quick steps

Confirm there is enough free space
Verify the format is compatible
Check ownership in Sharing & Permissions
Repair disk errors with Disk Utility

Paraphrased from the source. Menus can differ by version, so check the original for full details.

Read the full article on support.apple.com

Source: If your Mac can't save files to an external drive by Apple Support. Licence: Link only (©).

Source reviewed: 2026-11-02
Link checked: 2026-11-02
Tested hands-on: Not by Oddbyte.Me

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