Android Studio - UNEXPECTED TOP-LEVEL EXCEPTION:

Question

I have built a new project in Android Studio using the new project templates provided as part of the tool. All of the code has been generated by Studio I have not made any amendments yet.

I am attempting to run the code but the app fails with the following errors, not sure what the problem is so any help appreciated.

UNEXPECTED TOP-LEVEL EXCEPTION:
com.android.dex.DexException: Multiple dex files define Landroid/support/v7/app/ActionBar$Callback;
    at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:594)
    at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:552)
    at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:533)
    at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:170)
    at com.android.dx.merge.DexMerger.merge(DexMerger.java:188)
    at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:439)
    at com.android.dx.command.dexer.Main.runMonoDex(Main.java:287)
    at com.android.dx.command.dexer.Main.run(Main.java:230)
    at com.android.dx.command.dexer.Main.main(Main.java:199)
    at com.android.dx.command.Main.main(Main.java:103)

 FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:dexDebug'.
> com.android.ide.common.internal.LoggedErrorException: Failed to run command:
    C:UsersRichardKavanaghAppDataLocalAndroidandroid-sdkuild-tools19.0.1dx.bat --dex --output D:AndroidProjectsMyHealthRecordappuildlibsapp-debug.dex D:AndroidProjectsMyHealthRecordappuildclassesdebug D:AndroidProjectsMyHealthRecordappuilddependency-cachedebug D:AndroidProjectsMyHealthRecordappuildpre-dexeddebugandroid-support-v7-appcompat-5a78dab7e2789bbe64f4bc80d106ca75c04dcf6f.jar D:AndroidProjectsMyHealthRecordappuildpre-dexeddebugclasses-f9b947272e9f33ba50355b52d82755584f9c0c58.jar D:AndroidProjectsMyHealthRecordappuildpre-dexeddebugsupport-v4-19.0.0-31a2c13df80d37d62ca50fec3bde6da0ca706223.jar
Error Code:
    2
Output:

    UNEXPECTED TOP-LEVEL EXCEPTION:
    com.android.dex.DexException: Multiple dex files define Landroid/support/v7/app/ActionBar$Callback;
        at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:594)
        at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:552)
        at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:533)
        at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:170)
        at com.android.dx.merge.DexMerger.merge(DexMerger.java:188)
        at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:439)
        at com.android.dx.command.dexer.Main.runMonoDex(Main.java:287)
        at com.android.dx.command.dexer.Main.run(Main.java:230)
        at com.android.dx.command.dexer.Main.main(Main.java:199)
        at com.android.dx.command.Main.main(Main.java:103)



* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 12.948 secs

Answer 1

Like everyone else said here, the support library (com.android.support) is being included more than once in your project. Try adding this in your build.gradle at the root level and it should exclude the support library from being exported via other project dependencies.

configurations {
    all*.exclude group: 'com.android.support', module: 'support-v4'
}

If you have more then one support libs included in the dependencies like this, you may want to remove one of them: