Session 'app': Error Launching activity

Question

After the Android Studio 2.0 update while the gradle build finishes I get this :

Session \'app\': Error Launching activity .

It prevents the app from starting

Answer 1

Just run adb uninstall <package name> in your terminal and reinstall the app again.

Hope it helps.

Answer 2

Adb also throws this error if applicationId, package of launching activity or module name contains error substring

Answer 3

I had this error because of my stupidity. In the manifest.xml I have wrongly declared two Activity as Launcher. Make sure you have only one activity as Launcher.

    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

   <activity android:name=".WelcomeActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </activity>

Answer 4

I had the same error as in the headline. after I changed the version name and version code in the gradle, the sync happened and then it worked. so maybe even only sync can help sometimes.

Answer 5

This is issue with 2.0+ studio

Issue 206036: No local changes, not deploying APK

I found the nice workaround here just add -r flag here in edit configurations and also disabling instant

Waiting to get Instant run Feature run smoothly soon with no type 3 error more!!

Answer 6

Uninstall App on your real device or emulator. Then Run again. It's worked for me. I used Android Studio 2.3.3