title: Execution failed for task ':app:transformClassesWithInstantRunVerifierForDebug'. > java.lang.NullPointerException (no error message)
body: <p>I am new to android studio would anyone please help? I get below error randomly when I run my app. Here is my Gradle output.</p>
  
  <p>I tried below links but not found proper solution for this</p>
  
  <p><a href="https://stackoverflow.com/questions/33913783/execution-failed-for-task-apptransformclasseswithdexfordebug">Execution failed for task &#39;:app:transformClassesWithDexForDebug&#39;</a></p>
  
  <p><a href="https://stackoverflow.com/questions/30558737/execution-failed-for-task-apppreparedebugandroidtestdependencies">Execution failed for task &#39;app:prepareDebugAndroidTestDependencies&#39;</a></p>
  
  <p>FAILURE: Build failed with an exception.</p>
  
  <p><strong>What went wrong:</strong></p>
  
  <blockquote>
    <p>Execution failed for task
    :app:transformClassesWithInstantRunVerifierForDebug'.
         java.lang.NullPointerException (no error message)
            Try:
        Run with --info or --debug option to get more log output.</p>
  </blockquote>
  
  <pre><code> Exception is:
  org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:transformClassesWithInstantRunVerifierForDebug'.
      at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:69)
      at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:46)
      at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecutionAnalysisTaskExecuter.java:35)
      at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:64)
      at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
      at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:52)
      at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
      at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:53)
      at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
      at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:203)
      at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:185)
      at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:62)
      at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:50)
      at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:54)
      at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:40)
  Caused by: java.lang.NullPointerException
      at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:213)
      at com.google.common.base.Optional.of(Optional.java:85)
      at com.android.build.gradle.internal.incremental.InstantRunBuildContext.setVerifierResult(InstantRunBuildContext.java:69)
      at com.android.build.gradle.internal.transforms.InstantRunVerifierTransform.doTransform(InstantRunVerifierTransform.java:142)
      at com.android.build.gradle.internal.transforms.InstantRunVerifierTransform.transform(InstantRunVerifierTransform.java:121)
      at com.android.build.gradle.internal.pipeline.TransformTask$2.call(TransformTask.java:151)
      at com.android.build.gradle.internal.pipeline.TransformTask$2.call(TransformTask.java:148)
      at com.android.builder.profile.ThreadRecorder$1.record(ThreadRecorder.java:55)
      at com.android.builder.profile.ThreadRecorder$1.record(ThreadRecorder.java:47)
      at com.android.build.gradle.internal.pipeline.TransformTask.transform(TransformTask.java:147)
      at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:75)
      at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.doExecute(AnnotationProcessingTaskFactory.java:244)
      at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:220)
      at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.execute(AnnotationProcessingTaskFactory.java:231)
      at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:209)
      at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
      at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
      ... 14 more
  
  
  BUILD FAILED
  
  Total time: 14.898 secs
  </code></pre>