Can't run app while setting up Crashlytics - NoClassDefFoundError thrown

Question

I'm trying to add Crashlytics into my Android app, but I can't get to run it because of a NoClassDefFoundError when I press the "Run" button in Eclipse.

I installed ADT version of Eclipse, with the Crashlytics plug-in, and then I run the Crashlytics assistant. When I reached the "Build & run your app to check Crashlytics is fine", I get the following stacktrace:

06-19 00:18:53.647: E/AndroidRuntime(25400): java.lang.NoClassDefFoundError: com.crashlytics.android.Crashlytics
06-19 00:18:53.647: E/AndroidRuntime(25400):    at <app_package>.gui.MainMenuActivity.onCreate(MainMenuActivity.java:24)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.app.Activity.performCreate(Activity.java:5206)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1083)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2064)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2125)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.app.ActivityThread.access$600(ActivityThread.java:140)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1227)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.os.Handler.dispatchMessage(Handler.java:99)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.os.Looper.loop(Looper.java:137)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at android.app.ActivityThread.main(ActivityThread.java:4898)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at java.lang.reflect.Method.invokeNative(Native Method)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at java.lang.reflect.Method.invoke(Method.java:511)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
06-19 00:18:53.647: E/AndroidRuntime(25400):    at dalvik.system.NativeStart.main(Native Method)

I've checked the project libraries and crashlytics.jar is there, and it's also in the build path. I also cleaned the project and deleted the bin folder. I haven't found any solution to this problem. I have added Crashlytics to other Android projects and I haven't had any problems, but this one has become a big failure.

Any help would be truly appreciated, I have no clue about what to do... Thanks, kind regards!

Answer 1

Marc from Crashlytics here. We've had a couple users resolve this issue by exporting the Crashlytics jar in the Eclipse project properties (check the export box in the Properties->Java Build Path->Order and Export screen). Then clean, rebuild, and launch the app. Let me know how it goes!