After Updating Android studio to 3.1.2 , I get “Failed to load AppCompat ActionBar with unknown error. ”

Question

I tried looking other similar questions on stackoverflow, they advice us to changw version of \"buildToolsVersion\" but I dont see word like that in my gradle file.

Answer 1

module app gradle file looks like this...In your file you are missing buildToolsVersion, adding this may help you

  apply plugin: 'com.android.application'

 android {
  //changes
  compileSdkVersion 26
buildToolsVersion "27.0.3"
 defaultConfig {
    applicationId "com.example.dhruv.testhello"
   minSdkVersion 24
    targetSdkVersion 26
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner 
 "android.support.test.runner.AndroidJUnitRunner"
 }
 buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 
  'proguard-rules.pro'
    }
    }
 }

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])

//changes
compile 'com.android.support:appcompat-v7:26.0.2'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso- 
core:3.0.2'
 }

Answer 2

At the time of this answer Android Studio 3.1.4 is out with Android Support 28.0.0 Release Candidate(Potential Final, Beta) so please update. Well, here is a config that will certainly work for you.

targetSdkVersion 28
com.android.support:*:28.0.0-rc01

Where * is the resource type.

Answer 3

I was helped by Hossein Seifi's reply but with a change

implementation 'com.android.support:design:28.0.0-alpha3'

to

implementation 'com.android.support:design:28.0.0-alpha1'

and click File -> Invalidate Caches / Restart

Answer 4

In styles.xml,

Changing the theme from Theme.AppCompat.Light.DarkActionBar to Base.Theme.AppCompat.Light.DarkActionBar has worked for me.

Answer 5

Open, res>values>styles.xml, here you will find a line:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

replace the line with:

<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">

That means: Add the word "Base." starting the name of the parent theme.

Answer 6

Open, res --> values --> styles.xml, here you will find a line like this:

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

change it to:

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">

In otherwords, change DarkActionBar to NoActionBar