Android Studio: Client not ready yet

Question

While launching an app, I am getting a message " Client not ready yet". Also, my device is showing" Waiting for debugger to attach ", followed by "Unfortunately, android app has stopped working". I have tried every possible solution available on discussion forums, but no solution is applying here.I also tried running a simple HELLO WORLD app to know whether there is some issue with my app code, but the same message is been shown. I tried the following things:

1. Reinstalling the deice drivers
2. Reinstalling the android studio
3. Installing LLDB
4. Using different device, different cable and port
5. adding android.os.Debug.waitForDebugger(); to the manifest file
6. Changing setting to MTP only
7. Removing all breakpoints

But nothing worked. What could be the root cause of this problem??

Answer 1

The activity has to be exported to be accessible from adb. If the Activity has an intent-filter it is exported by default. Otherwise add the exported flag:

<activity
    android:name=".my.MyActivity"
    android:exported="true"/>

This is the error you get when the activity is not exported and you run

adb shell am start -n "com.example/com.example.my.MyActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER

Error:

Permission Denial: starting Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.example/.my.MyActiviy } from null (pid=26721, uid=2000) not exported from uid 10304
    at android.os.Parcel.readException(Parcel.java:1620)
    at android.os.Parcel.readException(Parcel.java:1573)
    at android.app.ActivityManagerProxy.startActivityAsUser(ActivityManagerNative.java:2694)
    at com.android.commands.am.Am.runStart(Am.java:875)
    at com.android.commands.am.Am.onRun(Am.java:359)
    at com.android.internal.os.BaseCommand.run(BaseCommand.java:47)
    at com.android.commands.am.Am.main(Am.java:100)
    at com.android.internal.os.RuntimeInit.nativeFinishInit(Native Method)
    at com.android.internal.os.RuntimeInit.main(RuntimeInit.java:251)