Android Studio: Failed to load dx.jar

Question

When I run my module in Android Studio I get this error:

Error:Android Dex: [GradleDevBuild] Failed to load dx.jar

I have searched endlessly for a solution online but everything is related to eclipse, there is nothing when it comes to Android Studio.

The path to the dex.jar is C:\AndroidSdk\build-tools\26.0.0\lib\dex.jar So it does exists, I've moved it out of the folder and was notified that it moved so AS is aware of where it is. I have tried copying it into the root directory and into the platform-tools folder however that did nothing.

This is the full list of errors that all seem to be stemming from this dx.jar error.

Error:Android Dex: [GradleDevBuild] Failed to load dx.jar
Error:Android Dex: [GradleDevBuild] java.lang.ClassNotFoundException: com.android.dx.command.DxConsole
Error:Android Dex: [GradleDevBuild] at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
Error:Android Dex: [GradleDevBuild] at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
Error:Android Dex: [GradleDevBuild] at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
Error:Android Dex: [GradleDevBuild] at org.jetbrains.android.compiler.tools.AndroidDxRunner.loadDex(AndroidDxRunner.java:80)
Error:Android Dex: [GradleDevBuild] at org.jetbrains.android.compiler.tools.AndroidDxRunner.runDex(AndroidDxRunner.java:136)
Error:Android Dex: [GradleDevBuild] at org.jetbrains.android.compiler.tools.AndroidDxRunner.main(AndroidDxRunner.java:336)
Error:Android Dex: [GradleDevBuild] Exception in thread "main" java.lang.NullPointerException
Error:Android Dex: [GradleDevBuild] at org.jetbrains.android.compiler.tools.AndroidDxRunner.runDex(AndroidDxRunner.java:139)

Answer 1

I just clean installed Android Studio on OS X and Ubuntu and had the same issue. Fixed by downgrading the build tools to 25.0.3.

For @emjapeve:

• Select the SDK Manager (Tools/Android/SDK Manager).
• Hit the SDK Tools tab, by default this only shows current tool versions.
• Select the Show Package Details checkbox.

From here you can install / uninstall any versions you wish.