adb: device unauthorized. This adb server's $ADB_VENDOR_KEYS is not set
The phone hasn’t accepted your computer’s RSA key for USB debugging yet.
Seen on:
Android
Meaning
The first connection shows an “Allow USB debugging?” dialog on the phone. If it was dismissed, the key revoked, or the adb keys regenerated, the device stays unauthorized.
Common causes
- Prompt on the phone not accepted (screen locked)
- USB debugging authorizations revoked
- adb keys changed (~/.android/adbkey)
- Charge-only cable/USB mode
⚡ Quick fix
- Unlock the phone and accept the prompt (tick Always allow)
- Revoke authorizations in Developer options and reconnect
- Restart adb server
Detailed fix by platform
ADB
- kotlin
adb kill-server && adb start-server adb devices
How to diagnose
- Phone — Prompt visible?
- Keys — ~/.android/adbkey present?
- Cable — Data-capable?
🔧 Still not fixed?
Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:
Similar errors
- ActivityNotFoundException ActivityNotFoundException: Unable to find explicit activity class; have you declared this activity in your AndroidManifest.xml?
- adb server version doesn't match adb server version (41) doesn't match this client (39); killing...
- Can not perform this action after onSaveInstanceState IllegalStateException: Can not perform this action after onSaveInstanceState (fragment transaction)
Most viewed in Android
Other ways to find it
🧠 Still stuck? Analyze your error
Paste the full message, response headers or stack trace — we'll detect the platform and point to the most likely cause.
Was this page helpful?
Report a correction or suggest an improvement
Last updated 7 Oct 2026