Expo ADB server didn’t ack error

Ricky H. Putra
2 min readJan 30, 2021

So I was exploring latest Android Studio 4 upgrade and upgrading my old Expo projects with it. I hit error when executing expo start with android emulator running.

The error message is below:

Couldn’t start project on Android: adb E 1723 33490 usb_osx.cpp:138] Unable to create an interface plug-in (e00002be)
error: could not install *smartsocket* listener: Address already in use
ADB server didn’t ACK
* failed to start daemon *
error: cannot connect to daemon

Checked adb process is running but was unable to connect by Expo. Strange.

I figured out that I have two adb installation exists from Android Studio platform tools and from Expo itself. From Mac Activity Manager, search for adb, double click on it, then you will see process details, click on Open Files and Ports.

adb from SDK platform-tools (auto starts from IDE)
adb from expo-cli

When you run Android Studio, the IDE will automatically starts the adb from SDK path which causing Expo to not able to use its own adb.

I killed adb process from SDK platform-tools, run “expo start” again, resolved the issue as Expo starts its own adb process.

Then I tried to upgrade expo-cli to latest version (4.1.4). Restart android emulator and Android Studio. When running “expo start” this time, it killed adb from SDK platform-tools and starting its own adb successfully. I am not sure if this issue arises from SDK platform-tools upgrade or expo upgrade. Troubleshooting android emulator related issues could be tricky and I hope this article could help people who have similar issue with me here. Cheers.

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Ricky H. Putra

Leading digitization initiatives in AwanTunai focusing on strengthening Indonesia MSME businesses with technology. Software Dev | Automation | Data Science | AI