Error: device offline

Question

The emulator is running. But when I write adb shell in my shell I get:

error:device offline

What is the reason for

Answer 1

If you are on Linux or Mac, and assuming the offline device is 'emulator-5554', you can run the following:

netstat -tulpn|grep 5554

Which yields the following output:

tcp        0      0 127.0.0.1:5554          0.0.0.0:*               LISTEN      4848/emulator64-x86
tcp        0      0 127.0.0.1:5555          0.0.0.0:*               LISTEN      4848/emulator64-x86

This tells me that the process id 4848 is still listening on port 5554. You can now kill that process with:

sudo kill -9 4848

and the ghost offline-device is no more!