Business Central is unable to start with error "no marshaller for type: org.guvnor.structure.contributors.Contributor" after migrating to 7.12.0

Issue

• After upgrading to RHPAM 7.12.0 from 7.11 version, Business Central is unable to start with the following exception:

  13:40:37,869 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-7) MSC000001: Failed to start service jboss.deployment.unit."business-central.war".WeldStartService: org.jboss.msc.service.StartException in service jboss.deployment.unit."business-central.war".WeldStartService: Failed to start service
      at org.jboss.msc.service.ServiceControllerImpl$StartTask.execute(ServiceControllerImpl.java:1731)
      at org.jboss.msc.service.ServiceControllerImpl$ControllerTask.run(ServiceControllerImpl.java:1559)
      at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
      at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1990)
      at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486)
      at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377)
      at java.lang.Thread.run(Thread.java:748)
       ...
  Caused by: org.jboss.errai.marshalling.client.api.exceptions.MarshallingException: Failed to demarshall an instance of org.guvnor.structure.organizationalunit.config.SpaceInfo
      at org.jboss.errai.marshalling.server.marshallers.DefaultDefinitisameonMarshaller.demarshall(DefaultDefinitionMarshaller.java:180)
      at org.jboss.errai.marshalling.client.marshallers.ObjectMarshaller.demarshall(ObjectMarshaller.java:88)
      at org.jboss.errai.marshalling.client.marshallers.ObjectMarshaller.doNotNullDemarshall(ObjectMarshaller.java:112)
      at org.jboss.errai.marshalling.client.marshallers.AbstractNullableMarshaller.demarshall(AbstractNullableMarshaller.java:35)
      at org.jboss.errai.marshalling.client.Marshalling.fromJSON(Marshalling.java:277)
      at org.jboss.errai.marshalling.client.Marshalling.fromJSON(Marshalling.java:249)
      at org.jboss.errai.marshalling.client.Marshalling.fromJSON(Marshalling.java:200)
      at org.jboss.errai.marshalling.client.Marshalling.fromJSON(Marshalling.java:319)
      at org.uberfire.backend.server.io.object.ObjectStorageImpl.read(ObjectStorageImpl.java:65)
      ... 54 more
  Caused by: java.lang.RuntimeException: no marshaller for type: org.guvnor.structure.contributors.Contributor
      at org.jboss.errai.marshalling.client.marshallers.AbstractCollectionMarshaller.marshallToCollection(AbstractCollectionMarshaller.java:87)
      at org.jboss.errai.marshalling.client.marshallers.ListMarshaller.doDemarshall(ListMarshaller.java:47)
      at org.jboss.errai.marshalling.client.marshallers.ListMarshaller.doDemarshall(ListMarshaller.java:34)
      at org.jboss.errai.marshalling.client.marshallers.AbstractCollectionMarshaller.doDemarshall(AbstractCollectionMarshaller.java:48)
      at org.jboss.errai.marshalling.client.marshallers.AbstractCollectionMarshaller.doDemarshall(AbstractCollectionMarshaller.java:33)
      at org.jboss.errai.marshalling.client.marshallers.AbstractBackReferencingMarshaller.demarshall(AbstractBackReferencingMarshaller.java:76)
      at org.jboss.errai.marshalling.client.marshallers.ObjectMarshaller.demarshall(ObjectMarshaller.java:88)
      at org.jboss.errai.marshalling.client.marshallers.ObjectMarshaller.doNotNullDemarshall(ObjectMarshaller.java:112)
      at org.jboss.errai.marshalling.client.marshallers.AbstractNullableMarshaller.demarshall(AbstractNullableMarshaller.java:35)
      at org.jboss.errai.marshalling.server.marshallers.DefaultDefinitionMarshaller.demarshall(DefaultDefinitionMarshaller.java:127)
      ... 62 more
  

• migration-tool.sh fails with the exception no marshaller for type: org.guvnor.structure.contributors.Contributor;