Troubleshooting
Common issues and how to fix them. Start by running adb devices in Terminal to see what state your device is in.
"No devices found" / empty list
adb devices shows nothing after "List of devices attached"
Causes:
- USB debugging not enabled. Enable it in Developer Options.
- Bad cable. Some USB-C cables are charge-only (no data). Try a different cable — ideally the one that came with your device.
- USB mode set to "Charging only". Pull down the notification shade on your device, tap the USB notification, and switch to "File transfer" or "PTP".
- ADB not installed. Run
adb version to check. If not found, install ADB.
Fix: Try restarting the ADB server:
adb kill-server
adb start-server
adb devices
"unauthorized"
adb devices shows XXXXXXXXX unauthorized
Your device hasn't authorized this Mac yet.
- Check your device screen — there should be an "Allow USB debugging?" dialog
- Check "Always allow from this computer"
- Tap Allow
If you don't see the dialog:
- Unplug and replug the USB cable
- Or revoke USB debugging authorizations: Developer Options → Revoke USB debugging authorizations, then reconnect
"offline"
adb devices shows XXXXXXXXX offline
The device is connected but not responding to ADB commands.
- Unplug and replug the USB cable
- Restart the ADB server:
adb kill-server && adb start-server
- If it persists, restart the device
- Try a different USB port on your Mac
"no permissions" (rare on macOS)
adb devices shows XXXXXXXXX no permissions
This is more common on Linux, but can happen on macOS if the ADB server was started as root.
adb kill-server
adb start-server
adb devices
macOS blocks ADB
"adb" cannot be opened because the developer cannot be verified.
- Go to System Settings → Privacy & Security
- Scroll down — you'll see a message about
adb being blocked
- Click "Allow Anyway"
- Run
adb devices again and click "Open" when prompted
SuperMirror says "No ADB found"
SuperMirror checks these locations for ADB:
/opt/homebrew/bin/adb (Apple Silicon Homebrew)/usr/local/bin/adb (Intel Homebrew)- Your shell's PATH (via
which adb)
- Bundled ADB in the app bundle
If ADB works in Terminal but not in SuperMirror, it may be installed in a non-standard location. The simplest fix:
brew install android-platform-tools
SuperMirror asks for Screen Recording permission
SuperMirror needs Screen Recording to capture your Mac's virtual display. When prompted:
- Click Grant in the setup wizard
- Toggle SuperMirror ON in System Settings → Privacy & Security → Screen Recording
- Quit and reopen SuperMirror (macOS requires a restart after granting)
Device shows black screen / no image
If mirroring starts but the Android device shows nothing:
- Check the ADB reverse tunnel: SuperMirror should show "ADB connected" in the menu bar
- Try stopping and restarting mirroring
- Check if the companion app launched on the device (should show a SuperMirror loading screen)
- Try "Reconnect" in the SuperMirror menu bar
Still stuck?
Open an issue on GitHub with:
- Your Mac model and macOS version
- Your Android device model
- Output of
adb devices
- What you see in the SuperMirror menu bar