Android : ClassNotFoundException - android-studio

Question

I'm getting this wierd error. When I came back to work yesterday night, I was facing this error. What I didn't understand is that I never changed anything in the code. It feels like it came out of the blue.
07-21 01:23:52.051 27020-27020/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.thinkinetics.rob.routinebuilder, PID: 27020
java.lang.RuntimeException: Unable to instantiate service com.thinkinetics.rob.RoutineWatchface: java.lang.ClassNotFoundException: Didn't find class "com.thinkinetics.rob.RoutineWatchface" on path: DexPathList[[zip file "/data/app/com.thinkinetics.rob.routinebuilder-2/base.apk"],nativeLibraryDirectories=[/data/app/com.thinkinetics.rob.routinebuilder-2/lib/arm, /vendor/lib, /system/lib]]
at android.app.ActivityThread.handleCreateService(ActivityThread.java:2862)
at android.app.ActivityThread.-wrap4(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1427)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5422)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.thinkinetics.rob.RoutineWatchface" on path: DexPathList[[zip file "/data/app/com.thinkinetics.rob.routinebuilder-2/base.apk"],nativeLibraryDirectories=[/data/app/com.thinkinetics.rob.routinebuilder-2/lib/arm, /vendor/lib, /system/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at android.app.ActivityThread.handleCreateService(ActivityThread.java:2859)
at android.app.ActivityThread.-wrap4(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1427) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5422) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
Suppressed: java.lang.ClassNotFoundException: Didn't find class "com.thinkinetics.rob.RoutineWatchface" on path: DexPathList[[dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-support-annotations-23.0.0_46201fc775bd6a2a1b3e71eae86ef67f12babd28-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_9-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_8-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_7-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_6-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_5-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_4-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_3-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_2-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_1-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-slice_0-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-internal_impl-23.0.0_93b2086be48ba8bf011786c70052b2e5db3ad593-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-com.google.android.support-wearable-1.3.0_c1d538a0bc8f53c23014746aa746d7950ae7bc3a-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-com.google.android.gms-play-services-wearable-8.4.0_921a6b02116cb3c5229600c4895d4c7fb55e5cef-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-com.google.android.gms-play-services-basement-8.4.0_3194cc3fb6ccb6c92a69d7fc4ace71b161b64889-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-com.google.android.gms-play-services-base-8.4.0_30a8813ef567e92576c485da70ce277d4fc2397e-classes.dex", dex file "/data/data/com.thinkinetics.rob.routinebuilder/files/instant-run/dex/slice-com.android.support-support-v4-23.0.0_7bc710f5526f9681c52eb6e494ababfb
Note: I did search for other questions with the same issue and I did find some. However, I followed every advice on those posts and it did not help me. After wasting my whole night I thought it would be a good idea to post here.
I'm not sure which parts of my code, if any, I should post along with this so I'll look at this actively and edit if necessary.
Here is the manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.thinkinetics.rob">
<uses-feature android:name="android.hardware.type.watch" />
<!-- Required to act as a custom watch face. -->
<uses-permission android:name="com.google.android.permission.PROVIDE_BACKGROUND" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.VIBRATE"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#android:style/Theme.DeviceDefault">
<service
android:name=".RoutineWatchface"
android:label="#string/my_digital_name"
android:permission="android.permission.BIND_WALLPAPER">
<meta-data
android:name="android.service.wallpaper"
android:resource="#xml/watch_face" />
<meta-data
android:name="com.google.android.wearable.watchface.preview"
android:resource="#drawable/preview_digital" />
<meta-data
android:name="com.google.android.wearable.watchface.preview_circular"
android:resource="#drawable/preview_digital_circular" />
<intent-filter>
<action android:name="android.service.wallpaper.WallpaperService" />
<category android:name="com.google.android.wearable.watchface.category.WATCH_FACE" />
</intent-filter>
</service>
<meta-data
android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />
</application>
</manifest>
Thank you.

Answer 1

I encountered the same issue just now. I uninstalled the app from device, rebuilt the project and then installed again. This time I did not face the problem, and it worked fine.
It might be some intermittent bug with instant-run feature in studio.