After upgrade android version getting “Duplicate class android.support.v4.app.INotificationSideChannel”

Question

before android update 3.4 my application run perfectly but after upgrade android my application getting merging error:

\"Duplicate class android.support.v4.         


        

Answer 1

Why did this happen?

Because after upgrade, androidx.core:core is accessed somewhere, when your project is still not using androidx. So classes like INotificationSideChannel and many others are now found at two places - androidx.core:core and com.android.support:support-compat. That's why this error occured.

Solution?

You need to migrate to AndroidX which you should have done already. If you don't know about AndroidX. Please read What is AndroidX?

How to migrate current project

In Android Studio 3.2 (September 2018), there is direct option to migrate existing project to AndroidX. This refract all packages automatically.

Before you migrate, it is strongly recommended to backup your project.

Existing project

• Android Studio > Refactor Menu > Migrate to AndroidX...
• It will analysis and will open Refractor window in bottom. Accept changes to be done.

New project

Put these flags in your gradle.properties

android.enableJetifier=true
android.useAndroidX=true

Check @Library mappings for equal AndroidX package.

Check @Official page of Migrate to AndroidX