A USB accessory does not work with your Mac
A known, trusted accessory; Mac
When to use this: A USB accessory does not work with your Mac — use these initial checks when this matches your situation. On a work or school device, follow your organization's policies and stop if a setting is managed.
- Check the accessory’s power and cable connection.
- Confirm the cable and adapter support the accessory, not just charging.
- After safely ejecting storage devices, try a direct connection instead of a hub.
- On Macs that ask, approve only the trusted accessory you just connected.
- Reopen the app that uses it.
Check the result: The intended app recognizes the accessory.
Stop and get help when needed: Never format an unreadable drive as a troubleshooting shortcut. Stop for damaged connectors, unusual heat or files you cannot afford to lose.
Need hands-on help?: Request DefenderTech support for individualized investigation or changes. We will explain the scope and estimate and ask for authorization before paid work begins. Do not include passwords, recovery keys or verification codes in your request.
Official references: - Apple guidance: https://support.apple.com/en-bw/guide/mac-help/mchlf779ae93/mac
Updated 2026-09-30