Hi Community,
I have an issue using a standalone rule-task.
Situation: There is process-model including a rule-task deployed via REST at a standalone process-engine - no additional java-code/-classes at all. The process-variables of a process-instance contain a complex object of a specific type, serialized as json. When it comes to the rule task, the engine throws the following error: Failed to parse type 'org.example.my.Obj' (remaining: ''): Cannot locate class 'org.example.my.Obj', problem: org.example.my.Obj
Fair enough, the engine cannot know about this type, but: the rule really does not need to know, because this variable is never accessed there. For instance: as soon as the variable is deleted (in Cockpit) or overwritten by a simple type using an input-mapping at the rule-task in the bpmn-file, everything is fine.
Any idea? Is this on purpose, or do I miss a point?
Best regards,
Florian 
(Tested also with Camunda 7.12)
Stacktrace
org.camunda.bpm.engine.ProcessEngineException: Cannot deserialize object in variable 'obj': SPIN/JACKSON-JSON-01007 Cannot construct java type from string 'org.example.my.Obj'
at org.camunda.bpm.engine.impl.variable.serializer.AbstractSerializableValueSerializer.readValue(AbstractSerializableValueSerializer.java:85) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.variable.serializer.AbstractSerializableValueSerializer.readValue(AbstractSerializableValueSerializer.java:31) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.util.TypedValueField.getTypedValue(TypedValueField.java:115) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.VariableInstanceEntity.getTypedValue(VariableInstanceEntity.java:282) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.core.variable.scope.AbstractVariableScope.getTypedValueFromVariableInstance(AbstractVariableScope.java:173) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.core.variable.scope.AbstractVariableScope.getVariableTyped(AbstractVariableScope.java:159) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.core.variable.scope.AbstractVariableScope.getVariableTyped(AbstractVariableScope.java:155) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.dmn.invocation.VariableScopeContext.resolve(VariableScopeContext.java:41) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.buildVariableMapFromVariableContext(DefaultDmnDecisionContext.java:104) ~[camunda-engine-dmn-7.14.0.jar:7.14.0]
at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.evaluateDecision(DefaultDmnDecisionContext.java:75) ~[camunda-engine-dmn-7.14.0.jar:7.14.0]
at org.camunda.bpm.dmn.engine.impl.DefaultDmnEngine.evaluateDecision(DefaultDmnEngine.java:167) ~[camunda-engine-dmn-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.dmn.invocation.DecisionInvocation.invoke(DecisionInvocation.java:57) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:58) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocationInContext(DefaultDelegateInterceptor.java:92) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocation(DefaultDelegateInterceptor.java:63) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.util.DecisionEvaluationUtil.invoke(DecisionEvaluationUtil.java:103) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.util.DecisionEvaluationUtil.evaluateDecision(DecisionEvaluationUtil.java:74) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.bpmn.behavior.DmnBusinessRuleTaskActivityBehavior$1.call(DmnBusinessRuleTaskActivityBehavior.java:56) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.bpmn.behavior.DmnBusinessRuleTaskActivityBehavior$1.call(DmnBusinessRuleTaskActivityBehavior.java:53) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.bpmn.behavior.AbstractBpmnActivityBehavior.executeWithErrorPropagation(AbstractBpmnActivityBehavior.java:90) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.bpmn.behavior.DmnBusinessRuleTaskActivityBehavior.execute(DmnBusinessRuleTaskActivityBehavior.java:53) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute$2.callback(PvmAtomicOperationActivityExecute.java:61) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute$2.callback(PvmAtomicOperationActivityExecute.java:50) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.continueIfExecutionDoesNotAffectNextOperation(PvmExecutionImpl.java:2036) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute.execute(PvmAtomicOperationActivityExecute.java:42) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute.execute(PvmAtomicOperationActivityExecute.java:31) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:131) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:111) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:86) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:628) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:602) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl$6.callback(PvmExecutionImpl.java:1975) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl$6.callback(PvmExecutionImpl.java:1972) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.continueExecutionIfNotCanceled(PvmExecutionImpl.java:2042) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.dispatchDelayedEventsAndPerformOperation(PvmExecutionImpl.java:1991) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.dispatchDelayedEventsAndPerformOperation(PvmExecutionImpl.java:1972) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(PvmAtomicOperationTransitionNotifyListenerStart.java:60) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(PvmAtomicOperationTransitionNotifyListenerStart.java:30) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:66) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:131) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:111) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:86) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:76) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:637) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:612) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:62) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:131) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:111) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:86) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:76) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:637) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:612) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:62) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:131) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:111) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:86) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:76) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:637) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:612) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:62) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:131) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:111) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:86) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:628) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:602) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationTransitionCreateScope.scopeCreated(PvmAtomicOperationTransitionCreateScope.java:38) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationCreateScope.execute(PvmAtomicOperationCreateScope.java:54) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationCreateScope.execute(PvmAtomicOperationCreateScope.java:28) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:131) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:118) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:86) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:76) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.jobexecutor.AsyncContinuationJobHandler.execute(AsyncContinuationJobHandler.java:81) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.jobexecutor.AsyncContinuationJobHandler.execute(AsyncContinuationJobHandler.java:40) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.persistence.entity.JobEntity.execute(JobEntity.java:133) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.cmd.ExecuteJobsCmd.execute(ExecuteJobsCmd.java:110) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.cmd.ExecuteJobsCmd.execute(ExecuteJobsCmd.java:43) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:28) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:110) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.spring.SpringTransactionInterceptor$1.doInTransaction(SpringTransactionInterceptor.java:46) ~[camunda-engine-spring-7.14.0.jar:7.14.0]
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140) ~[spring-tx-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.camunda.bpm.engine.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:44) ~[camunda-engine-spring-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.ProcessApplicationContextInterceptor.execute(ProcessApplicationContextInterceptor.java:70) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.CommandCounterInterceptor.execute(CommandCounterInterceptor.java:35) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:33) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.jobexecutor.ExecuteJobHelper.executeJob(ExecuteJobHelper.java:57) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.jobexecutor.ExecuteJobsRunnable.executeJob(ExecuteJobsRunnable.java:110) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.jobexecutor.ExecuteJobsRunnable.run(ExecuteJobsRunnable.java:71) ~[camunda-engine-7.14.0.jar:7.14.0]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_275]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_275]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_275]
Caused by: org.camunda.spin.json.SpinJsonDataFormatException: SPIN/JACKSON-JSON-01007 Cannot construct java type from string 'org.example.my.Obj'
at org.camunda.spin.impl.json.jackson.JacksonJsonLogger.unableToConstructJavaType(JacksonJsonLogger.java:76) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
at org.camunda.spin.impl.json.jackson.format.JacksonJsonDataFormat.constructJavaTypeFromCanonicalString(JacksonJsonDataFormat.java:167) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
at org.camunda.spin.impl.json.jackson.format.JacksonJsonDataFormatMapper.mapInternalToJava(JacksonJsonDataFormatMapper.java:83) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
at org.camunda.spin.plugin.impl.SpinObjectValueSerializer.deserializeFromByteArray(SpinObjectValueSerializer.java:101) ~[camunda-engine-plugin-spin-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.variable.serializer.AbstractObjectValueSerializer.deserializeFromByteArray(AbstractObjectValueSerializer.java:119) ~[camunda-engine-7.14.0.jar:7.14.0]
at org.camunda.bpm.engine.impl.variable.serializer.AbstractSerializableValueSerializer.readValue(AbstractSerializableValueSerializer.java:83) ~[camunda-engine-7.14.0.jar:7.14.0]
... 96 common frames omitted
Caused by: java.lang.IllegalArgumentException: Failed to parse type 'org.example.my.Obj' (remaining: ''): Cannot locate class 'org.example.my.Obj', problem: org.example.my.Obj
at spinjar.com.fasterxml.jackson.databind.type.TypeParser._problem(TypeParser.java:91) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
at spinjar.com.fasterxml.jackson.databind.type.TypeParser.findClass(TypeParser.java:85) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
at spinjar.com.fasterxml.jackson.databind.type.TypeParser.parseType(TypeParser.java:47) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
at spinjar.com.fasterxml.jackson.databind.type.TypeParser.parse(TypeParser.java:33) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
at spinjar.com.fasterxml.jackson.databind.type.TypeFactory.constructFromCanonical(TypeFactory.java:582) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
at org.camunda.spin.impl.json.jackson.format.JacksonJsonDataFormat.constructJavaTypeFromCanonicalString(JacksonJsonDataFormat.java:165) ~[camunda-spin-dataformat-all-1.10.0.jar:1.10.0]
... 100 common frames omitted