UnsupportedClassVersionError for org/eclipse/core/runtime/OperationCanceledException

[Anitha-y]

Hi,

I am getting error while performing ./gradlew shadowjar. It is not able to find the compatible versions. Tools used are gradle version 3.0, shadowjar 1.2.4 and java 8. The task io.typefox.xtext.langserver.example:generateXtextLanguage was run without any issue. However for task generateXtext it is failing with UnsupportedClassVersionError for org/eclipse/core/runtime/OperationCanceledException. It says that this class is run with Java runtime 55.0 while java 8 supports only till version 52.0.

Where is this build picking up file built with higher version of java? Am i doing something wrong in my settings?

Stacktrace:
Starting a Gradle Daemon (subsequent builds will be faster)
:io.typefox.xtext.langserver.example:generateXtextLanguage UP-TO-DATE
:io.typefox.xtext.langserver.example:generateXtext FAILED

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':io.typefox.xtext.langserver.example:generateXtext'.

com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0

• Try:
  Run with --info or --debug option to get more log output.

• Exception is:
  org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':io.typefox.xtext.langserver.example:generateXtext'.
  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$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:74)
  at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:55)
  at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:32)
  at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:110)
  at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:37)
  at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:37)
  at org.gradle.execution.DefaultBuildExecuter.access$000(DefaultBuildExecuter.java:23)
  at org.gradle.execution.DefaultBuildExecuter$1.proceed(DefaultBuildExecuter.java:43)
  at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
  at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:37)
  at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:30)
  at org.gradle.initialization.DefaultGradleLauncher$4.run(DefaultGradleLauncher.java:153)
  at org.gradle.internal.Factories$1.create(Factories.java:22)
  at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:91)
  at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:53)
  at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:150)
  at org.gradle.initialization.DefaultGradleLauncher.access$200(DefaultGradleLauncher.java:32)
  at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:98)
  at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:92)
  at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:91)
  at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:63)
  at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:92)
  at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:83)
  at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:94)
  at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.java:28)
  at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
  at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:43)
  at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:28)
  at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:82)
  at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:49)
  at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:59)
  at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:49)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:26)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.java:34)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:74)
  at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:72)
  at org.gradle.util.Swapper.swap(Swapper.java:38)
  at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:72)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.LogAndCheckHealth.execute(LogAndCheckHealth.java:55)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:60)
  at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:72)
  at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.HintGCAfterBuild.execute(HintGCAfterBuild.java:44)
  at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
  at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:50)
  at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:240)
  at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:54)
  at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:40)
  Caused by: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2049)
  at com.google.common.cache.LocalCache.get(LocalCache.java:3953)
  at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3976)
  at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4960)
  at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4966)
  at com.google.inject.internal.FailableCache.get(FailableCache.java:48)
  at com.google.inject.internal.ConstructorInjectorStore.get(ConstructorInjectorStore.java:50)
  at com.google.inject.internal.ConstructorBindingImpl.initialize(ConstructorBindingImpl.java:136)
  at com.google.inject.internal.InjectorImpl.initializeJitBinding(InjectorImpl.java:547)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBinding(InjectorImpl.java:884)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive(InjectorImpl.java:805)
  at com.google.inject.internal.InjectorImpl.getJustInTimeBinding(InjectorImpl.java:282)
  at com.google.inject.internal.InjectorImpl.getBindingOrThrow(InjectorImpl.java:214)
  at com.google.inject.internal.InjectorImpl.getProviderOrThrow(InjectorImpl.java:1006)
  at com.google.inject.internal.InjectorImpl.getProvider(InjectorImpl.java:1038)
  at com.google.inject.internal.InjectorImpl.getProvider(InjectorImpl.java:1001)
  at com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1051)
  at org.xtext.gradle.builder.XtextGradleBuilder.(XtextGradleBuilder.java:87)
  at org.xtext.gradle.builder.XtextGradleBuilderFactory.get(XtextGradleBuilderFactory.java:14)
  at org.xtext.gradle.tasks.internal.IncrementalXtextBuilderProvider.createBuilder(IncrementalXtextBuilderProvider.java:80)
  at org.xtext.gradle.tasks.internal.IncrementalXtextBuilderProvider.getBuilder(IncrementalXtextBuilderProvider.java:39)
  at org.xtext.gradle.tasks.XtextGenerate.initializeBuilder(XtextGenerate.java:417)
  at org.xtext.gradle.tasks.XtextGenerate.generate(XtextGenerate.java:146)
  at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:75)
  at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$IncrementalTaskAction.doExecute(DefaultTaskClassInfoStore.java:155)
  at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:126)
  at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:115)
  at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
  at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
  ... 68 more
  Caused by: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2049)
  at com.google.common.cache.LocalCache.get(LocalCache.java:3953)
  at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3976)
  at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4960)
  at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4966)
  at com.google.inject.internal.FailableCache.get(FailableCache.java:48)
  at com.google.inject.internal.MembersInjectorStore.get(MembersInjectorStore.java:68)
  at com.google.inject.internal.ConstructorInjectorStore.createConstructor(ConstructorInjectorStore.java:74)
  at com.google.inject.internal.ConstructorInjectorStore.access$000(ConstructorInjectorStore.java:29)
  at com.google.inject.internal.ConstructorInjectorStore$1.create(ConstructorInjectorStore.java:37)
  at com.google.inject.internal.ConstructorInjectorStore$1.create(ConstructorInjectorStore.java:33)
  at com.google.inject.internal.FailableCache$1.load(FailableCache.java:37)
  at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3529)
  at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2278)
  at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2155)
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2045)
  ... 96 more
  Caused by: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2049)
  at com.google.common.cache.LocalCache.get(LocalCache.java:3953)
  at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3976)
  at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4960)
  at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4966)
  at com.google.inject.internal.FailableCache.get(FailableCache.java:48)
  at com.google.inject.internal.ConstructorInjectorStore.get(ConstructorInjectorStore.java:50)
  at com.google.inject.internal.ConstructorBindingImpl.initialize(ConstructorBindingImpl.java:136)
  at com.google.inject.internal.InjectorImpl.initializeJitBinding(InjectorImpl.java:547)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBinding(InjectorImpl.java:884)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive(InjectorImpl.java:805)
  at com.google.inject.internal.InjectorImpl.getJustInTimeBinding(InjectorImpl.java:282)
  at com.google.inject.internal.InjectorImpl.getBindingOrThrow(InjectorImpl.java:214)
  at com.google.inject.internal.InjectorImpl.createProviderBinding(InjectorImpl.java:343)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBinding(InjectorImpl.java:842)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive(InjectorImpl.java:805)
  at com.google.inject.internal.InjectorImpl.getJustInTimeBinding(InjectorImpl.java:282)
  at com.google.inject.internal.InjectorImpl.getBindingOrThrow(InjectorImpl.java:214)
  at com.google.inject.internal.SingleFieldInjector.(SingleFieldInjector.java:42)
  at com.google.inject.internal.MembersInjectorStore.getInjectors(MembersInjectorStore.java:131)
  at com.google.inject.internal.MembersInjectorStore.createWithListeners(MembersInjectorStore.java:98)
  at com.google.inject.internal.MembersInjectorStore.access$000(MembersInjectorStore.java:37)
  at com.google.inject.internal.MembersInjectorStore$1.create(MembersInjectorStore.java:45)
  at com.google.inject.internal.MembersInjectorStore$1.create(MembersInjectorStore.java:42)
  at com.google.inject.internal.FailableCache$1.load(FailableCache.java:37)
  at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3529)
  at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2278)
  at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2155)
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2045)
  ... 111 more
  Caused by: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2049)
  at com.google.common.cache.LocalCache.get(LocalCache.java:3953)
  at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3976)
  at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4960)
  at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4966)
  at com.google.inject.internal.FailableCache.get(FailableCache.java:48)
  at com.google.inject.internal.MembersInjectorStore.get(MembersInjectorStore.java:68)
  at com.google.inject.internal.ConstructorInjectorStore.createConstructor(ConstructorInjectorStore.java:74)
  at com.google.inject.internal.ConstructorInjectorStore.access$000(ConstructorInjectorStore.java:29)
  at com.google.inject.internal.ConstructorInjectorStore$1.create(ConstructorInjectorStore.java:37)
  at com.google.inject.internal.ConstructorInjectorStore$1.create(ConstructorInjectorStore.java:33)
  at com.google.inject.internal.FailableCache$1.load(FailableCache.java:37)
  at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3529)
  at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2278)
  at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2155)
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2045)
  ... 139 more
  Caused by: com.google.common.util.concurrent.ExecutionError: com.google.common.util.concurrent.ExecutionError: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2049)
  at com.google.common.cache.LocalCache.get(LocalCache.java:3953)
  at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3976)
  at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4960)
  at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4966)
  at com.google.inject.internal.FailableCache.get(FailableCache.java:48)
  at com.google.inject.internal.ConstructorInjectorStore.get(ConstructorInjectorStore.java:50)
  at com.google.inject.internal.ConstructorBindingImpl.initialize(ConstructorBindingImpl.java:136)
  at com.google.inject.internal.InjectorImpl.initializeJitBinding(InjectorImpl.java:547)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBinding(InjectorImpl.java:884)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive(InjectorImpl.java:805)
  at com.google.inject.internal.InjectorImpl.getJustInTimeBinding(InjectorImpl.java:282)
  at com.google.inject.internal.InjectorImpl.getBindingOrThrow(InjectorImpl.java:214)
  at com.google.inject.internal.SingleFieldInjector.(SingleFieldInjector.java:42)
  at com.google.inject.internal.MembersInjectorStore.getInjectors(MembersInjectorStore.java:131)
  at com.google.inject.internal.MembersInjectorStore.createWithListeners(MembersInjectorStore.java:98)
  at com.google.inject.internal.MembersInjectorStore.access$000(MembersInjectorStore.java:37)
  at com.google.inject.internal.MembersInjectorStore$1.create(MembersInjectorStore.java:45)
  at com.google.inject.internal.MembersInjectorStore$1.create(MembersInjectorStore.java:42)
  at com.google.inject.internal.FailableCache$1.load(FailableCache.java:37)
  at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3529)
  at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2278)
  at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2155)
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2045)
  ... 154 more
  Caused by: com.google.common.util.concurrent.ExecutionError: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2049)
  at com.google.common.cache.LocalCache.get(LocalCache.java:3953)
  at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3976)
  at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4960)
  at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4966)
  at com.google.inject.internal.FailableCache.get(FailableCache.java:48)
  at com.google.inject.internal.MembersInjectorStore.get(MembersInjectorStore.java:68)
  at com.google.inject.internal.ConstructorInjectorStore.createConstructor(ConstructorInjectorStore.java:74)
  at com.google.inject.internal.ConstructorInjectorStore.access$000(ConstructorInjectorStore.java:29)
  at com.google.inject.internal.ConstructorInjectorStore$1.create(ConstructorInjectorStore.java:37)
  at com.google.inject.internal.ConstructorInjectorStore$1.create(ConstructorInjectorStore.java:33)
  at com.google.inject.internal.FailableCache$1.load(FailableCache.java:37)
  at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3529)
  at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2278)
  at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2155)
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2045)
  ... 177 more
  Caused by: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
  at com.google.inject.spi.InjectionPoint.forConstructorOf(InjectionPoint.java:245)
  at com.google.inject.internal.ConstructorBindingImpl.create(ConstructorBindingImpl.java:99)
  at com.google.inject.internal.InjectorImpl.createUninitializedBinding(InjectorImpl.java:658)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBinding(InjectorImpl.java:882)
  at com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive(InjectorImpl.java:805)
  at com.google.inject.internal.InjectorImpl.getJustInTimeBinding(InjectorImpl.java:282)
  at com.google.inject.internal.InjectorImpl.getBindingOrThrow(InjectorImpl.java:214)
  at com.google.inject.internal.SingleFieldInjector.(SingleFieldInjector.java:42)
  at com.google.inject.internal.MembersInjectorStore.getInjectors(MembersInjectorStore.java:131)
  at com.google.inject.internal.MembersInjectorStore.createWithListeners(MembersInjectorStore.java:98)
  at com.google.inject.internal.MembersInjectorStore.access$000(MembersInjectorStore.java:37)
  at com.google.inject.internal.MembersInjectorStore$1.create(MembersInjectorStore.java:45)
  at com.google.inject.internal.MembersInjectorStore$1.create(MembersInjectorStore.java:42)
  at com.google.inject.internal.FailableCache$1.load(FailableCache.java:37)
  at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3529)
  at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2278)
  at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2155)
  at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2045)
  ... 192 more

BUILD FAILED

[cdietrich]

see eclipse-xtext/xtext#1976

[cdietrich]

workaround that may work for you with older xtext and xtext-gradle-plugin versions
itemis/xtext-languageserver-example@4b6cd46

[Anitha-y]

Tried this. Added it into the build.gradle file under xtext-dsl-language-server. But still getting the same error. Where is this picking up the class file org/eclipse/core/runtime/OperationCanceledException from?

[cdietrich]

this project uses STONEAGE version of as good as everything.
=> you see eclipse-xtext/xtext#1231 too
=> you need more constraints, update gradle and plugins
=> i have doubts anything of this runs with any up to date theia version

 git diff
diff --git a/xtext-dsl-language-server/build.gradle b/xtext-dsl-language-server/build.gradle
index d79f399..b8862ad 100644
--- a/xtext-dsl-language-server/build.gradle
+++ b/xtext-dsl-language-server/build.gradle
@@ -1,10 +1,11 @@
 buildscript {
        repositories {
                jcenter()
+               gradlePluginPortal()
        }
        dependencies {
-               classpath 'org.xtext:xtext-gradle-plugin:1.0.15'
-               classpath 'com.github.jengelman.gradle.plugins:shadow:1.2.4'
+               classpath 'org.xtext:xtext-gradle-plugin:2.1.0'
+               classpath "com.github.jengelman.gradle.plugins:shadow:5.2.0"
     }
 }

@@ -34,4 +35,12 @@ subprojects {
        configurations.all {
                exclude group: 'asm'
        }
+
+       configurations.all {
+        resolutionStrategy {
+                       force "org.eclipse.platform:org.eclipse.core.runtime:3.19.0"
+                       force "org.eclipse.platform:org.eclipse.equinox.common:3.13.0"
+        }
+    }
+
 }
diff --git a/xtext-dsl-language-server/gradle/wrapper/gradle-wrapper.properties b/xtext-dsl-language-server/gradle/wrapper/gradle-wrapper.properties
index 293fd09..4c46317 100644
--- a/xtext-dsl-language-server/gradle/wrapper/gradle-wrapper.properties
+++ b/xtext-dsl-language-server/gradle/wrapper/gradle-wrapper.properties
@@ -2,4 +2,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-bin.zip

you also need to check these workarounds for the test and for executing the plugin

is there a reason you dont simply build and deploy a vscode extension?