Introduction

When Android tooling says a device is connected but shows no permissions, the problem is usually not inside your app. It usually means the host machine can see the USB device, but adb does not have permission to access it, which is most common on Ubuntu or other Linux systems without the right plugdev membership or udev rules.

Confirm the Actual Error

Start by checking what adb sees.

adb devices -l

If the device appears with a state related to permissions instead of device, you are debugging host-to-device access, not Android Studio itself.

Also make sure USB debugging is enabled on the phone and that the phone accepted the computer's RSA fingerprint prompt.

Linux Fix: plugdev Group and udev Rules

According to the current Android device setup guidance, Ubuntu systems need two things for USB debugging to work reliably:

• your user must be in the plugdev group
• the system must have udev rules for Android devices

Add yourself to the group:

sudo usermod -aG plugdev "$LOGNAME"

Then install the common platform-tools rules package:

sudo apt-get update
sudo apt-get install -y android-sdk-platform-tools-common

After changing group membership, log out and back in so the new group takes effect.

Restart the ADB Server

Once permissions are fixed, restart the ADB server.

adb kill-server
adb start-server
adb devices -l

If the device still does not appear correctly, unplug and reconnect the cable and re-check the device screen for the USB debugging authorization prompt.

Check the USB Mode on the Device

Some phones connect in charge-only mode or a restricted USB mode by default. Open the USB settings on the device and make sure the connection is not blocked. Even though adb does not require file transfer mode specifically, a locked-down USB mode can interfere with debugging access on some devices.

It is also worth trying:

• a different USB cable
• a direct port instead of a hub
• unlocking the phone before connecting

Physical connection issues and host permissions often look similar from the IDE.

macOS and Windows Are Different

This specific no permissions message is mostly a Linux issue. On macOS, no extra udev configuration is needed. On Windows, the equivalent problem is usually a missing or incorrect OEM USB driver rather than Unix device permissions.

That matters because copying Linux udev advice to Windows will not help, and copying Windows driver advice to Ubuntu misses the actual fix.

Android Studio Versus Raw ADB

Android Studio uses ADB underneath. If adb devices -l does not show the device correctly, Android Studio will not fix it for you. Always debug the low-level ADB connection first.

This also means command-line verification is useful before changing IDE settings:

adb version
which adb

If multiple SDK installations exist, the IDE may be using one adb binary while your shell uses another.

Common Pitfalls

A common mistake is adding the user to plugdev and expecting the fix to apply immediately. Group membership changes usually require logging out and back in.

Another mistake is forgetting udev rules on Ubuntu. Without matching rules, the device may be visible to the system but still inaccessible to the user-level ADB process.

People also often keep retrying in Android Studio while ignoring the phone's USB debugging authorization dialog. Until that dialog is accepted, the host is not trusted.

Finally, do not ignore cables and USB hubs. Bad physical connections waste a lot of debugging time because they imitate software permission failures.

Summary

• 'no permissions usually means ADB lacks host-level access to the device.'
• On Ubuntu, make sure the user is in plugdev and Android udev rules are installed.
• Restart ADB and reconnect the device after fixing host permissions.
• Verify USB debugging and host authorization on the phone itself.
• Debug with adb devices -l first, because Android Studio depends on the same underlying connection.