error inflating ConstraintLayout in android studio

Question

I'm having problems with Android Studio. I recently upgraded my SDK Manager to include;

compile 'com.android.support.constraint:constraint-layout:1.0.0-beta5'

classpath is

 classpath 'com.android.tools.build:gradle:2.2.3'

Project builds fine. Intellisense and documentation works fine. But when I try to run (in debug) the app on my phone I get this error;

 Caused by: android.view.InflateException: Binary XML file line #2:
 Binary XML file line #2: Error inflating class ConstraintLayout
                   at android.view.LayoutInflater.inflate(LayoutInflater.java:539)
                   at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
                   at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
                   at com.android.internal.policy.PhoneWindow.setContentView(PhoneWindow.java:443)
                   at android.app.Activity.setContentView(Activity.java:2172)

I've synced gradle. I've restarted Android Studio. I've cleaned and rebuilt the project.

Any ideas on how to fix this? thanks!

-edit- XML looks like this;

<ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/PLAY_PARENT"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/greenfelt2"
android:padding="0dp">

Answer 1

You should add as below

<android.support.constraint.ConstraintLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:id="@+id/PLAY_PARENT"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:background="@drawable/greenfelt2"
 android:padding="0dp">

compile 'com.android.support.constraint:constraint-layout:1.0.2'

For the latest release check here

check out this project for more on ConstraintLayout Usage

Update

For those who are switching from android support to androidx, remember to change android.support.constraint.ConstraintLayout to androidx.constraintlayout.widget.ConstraintLayout

Answer 2

I don't know if this was solution 2 and half years ago, but today i had similar error. Found the answer right here: Error inflating class androidx.constraintlayout.ConstraintLayout after migration to androidx

Basically only xml tags of constraint layout should be renamed to these ->

androidx.constraintlayout.widget.ConstraintLayout

Answer 3

If You using androidx, you must use

androidx.constraintlayout.widget.ConstraintLayout

Answer 4

It may be number of reasons

1. dependency version issue (same like above)

2. out-of-memory issue : In my case I was added the high resolution image for background of the constraint-layout or in the same page(.xml file) we used the high resolution image for any imageview source.