Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'. > com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex

[faisal-khan16]

when i run the sample project i get the above mentioned error.Please help me out in solving it.

[Swavis]

Same issue - Unable to merge dex, @faisal-khan16 did you find the solution?

[jagadeesh-vadivel]

Same Issue -Do any one know the solution?

[lossen]

Same Issue :((((

[clearbrian]

when the dex error appear in red. Theres option to rerun in debug param.
This then shows error
Duplicate zip entry [gson-2.3.1.jar:com/google/gson/annotations/Expose.class
Caused by having gson.jar in the /libs and probably in the client
compile 'com.microsoft.projectoxford:vision:1.0.394'

/Cognitive-Vision-Android-master/Sample/app/libs/gson-2.3.1.jar

Ans: comment out the lines to include the lib in the project.

Note: other solutions to Dex error say to add
multiDexEnabled true
compile 'com.android.support:multidex:1.0.3'

But once I removed the compile jars the dex error went away.
I tend removed the
multiDexEnabled true
compile 'com.android.support:multidex:1.0.3'
and error didnt return so these arent needed

Note if you do have jar you need to include then just delete
/Cognitive-Vision-Android-master/Sample/app/libs/gson-2.3.1.jar
//compile files('libs/gson-2.3.1.jar')

FINAL WORKING GRADLE - 13 mar 2018

apply plugin: 'com.android.application'

android {
    compileSdkVersion 27


    //    Warning:The specified Android SDK Build Tools version (25.0.2) is ignored, as it is below the minimum supported version (26.0.2) for Android Gradle Plugin 3.0.1.
    //    Android SDK Build Tools 26.0.2 will be used.
    //    To suppress this warning, remove "buildToolsVersion '25.0.2'" from your build.gradle file, as each version of the Android Gradle Plugin now has a default version of the build tools.
    //
    //    remove "buildToolsVersion '25.0.2'"
    //buildToolsVersion "25.0.2"

    defaultConfig {
        applicationId "com.microsoft.projectoxford.visionsample"
        minSdkVersion 19
        targetSdkVersion 27
        versionCode 2
        versionName "1.1"

        //DEX ERROR - mentioned on Stackoverflow as solution but dex error disappear when you comment out compile files()/ compile fileTre
        //multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    //DEX ERROR - mentioned on Stackoverflow as solution but dex error disappear when you comment out compile files()/ compile fileTr
    //compile fileTree(dir: 'libs', include: ['*.jar'])


    // Use the following line to include client library for Vision API from Maven Central Repository
    compile 'com.microsoft.projectoxford:vision:1.0.394'
    compile 'com.android.support:appcompat-v7:27.1.0'


    //DEX ERROR FIX
    //Fixed by commenting this out and
    //compile files('libs/gson-2.3.1.jar')


    //DEX ERROR - mentioned on Stackoverflow as solution but dex error disappear when you comment out compile files()/ compile fileTre
    //left in in case error returns
    //compile 'com.android.support:multidex:1.0.3'
}