adb server version doesn't match this client

Question

Whenever I try to run adb devices:

            $ adb devices
            * daemon not running. starting it now *
            * daemon started su         


        

Answer 1

OS: Ubuntu

There are more than 1 adb are running. Check the current adb:

    which adb
    Expected Output : ANDROID_SDK/platform-tools/adb

Normally the result will be:

    /usr/bin/adb

Delete this older version by:

    cd /urs/bin
    sudo rm adb