我是android工作室的新手，有人请帮忙吗？当我运行我的应用程序时，我随机得到以下错误。这是我的Gradle输出。
我尝试了下面的链接，但找不到合适的解决方案
Execution failed for task ':app:transformClassesWithDexForDebug'
Execution failed for task 'app:prepareDebugAndroidTestDependencies'
失败：构建因异常而失败。
出了什么问题：
任务执行失败 ：应用程序：transformClassesWithInstantRunVerifierForDebug＆＃39 ;. java.lang.NullPointerException（无错误消息） 尝试： 使用--info或--debug选项运行以获得更多日志输出。
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