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

I spent a whole lot of hours on this exact issue. The "instant run" fix was a total fail. And I wasn't missing the android.intent.category.LAUNCHER I removed all applicable Android Studio and SDK code and re-installed. Still a no go.

Ultimately I think my issue was marginal hardware. I'm running on a laptop with a AMD A6-4400M processor. There is no hardware acceleration / virtualization tools available. I was just running the standard Android Studio / Google emulator. It was painfully slow, and although I was eventually able to see the emulator and interact with it, I was never able to connect the emulator to Android Studio to upload APK's.

But I did discover an awesome fix.

• Remove all Android Virtual Devices and install the GenyMotion Emulator (with VirtualBox).
• I've tried GenyMotion emulators before (with a Linux) and it didn't make much difference in load up speed.
• On this Windows 10 machine it works exceptionally well. Its pretty quick, easily connects to Android Studio and works well deploying my apps.
• GenyMotion offers one personal use device at no cost. Kudos to the GenyMotion team!

Answer provided here in case anybody else gets stuck with this error, possibly with this root cause.