adb devices return error: protocol fault (no status)

Question

My ADB stopped working recently. All commands results in error: protocol fault (no status).

Follow trace.

adb devices

system/core/adb/adb.c::main         


        

Answer 1

I had this problem on linux. I didn't realize I had an old adb on my path. Make sure that

which adb

and

which emulator

point to similar android sdk versions.

Answer 2

I had the same issue and found the problem: Android Studio.

Open the Android Studio menu Tools -> Android and uncheck Enable ADB integration.

adb devices should work (you might need adb kill-server first).

Then you can re-enable ADB integration in Studio.

Answer 3

This typically means, that your ADB service or your driver is outdated.
Since the drivers aren't updated most of the time, make sure you've installed the latest version of your Android SDK Platform-tools via the SDK Manager:

Answer 4

I recently got the same error, after installing a driver for the Moto X. I previously had the ADB and Fastboot quick install. I installed the driver, saw that the Moto X still wasn't registered, so uninstalled the driver again. Ten I got this error message. I opened Task Manager, killed the ADB.exe and then in Bash hit the adb device command. All was good again.