Session 'app' error while installing APK

Question

I am having difficulty importing a project written on Android Studio 1.1 into Android Studio 2.1.2. I keep getting this error whenever the gradle is building before testing

Answer 1

mi users if you are facing this type of issue follow these steps:

Step 1 : generate developer options as follow Settings>>About Device>>Click 7 times on MIUI Version>> It will Generate Developer Options.

Now Enable Following...

Step 2: Setting>Additional setting> Developer options> Enable USB Debugging

Step 3: Setting>Additional setting> Developer options> Enable Install via USB Note: Its Will get Enable Only If You Insert SIM In MI Device/Phone.

Step 4: Setting>Additional setting> Developer options> Enable Verify apps over USB.

all done now run the project and test....

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non mi user:

just enable once instant run options from the settings--> Build,Execution, Deployment-->Select Instant Run and Enable Check Click On OK...

Its Will Work....