Hi Maciej. Yes, it is a similar case than mine too. I have (for now, changing it) one session which I reload everytime I start the app, and I have an agent to rebuild my knowledge base. From time to time, I am facing a similar exception when loading the session, which I think it is caused to some changes in kbase:
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:88)
... 35 more
Caused by: java.lang.RuntimeException: Unable to load session snapshot
at org.drools.persistence.SessionMarshallingHelper.loadSnapshot(SessionMarshallingHelper.java:96)
at org.drools.persistence.SingleSessionCommandService.initKsession(SingleSessionCommandService.java:193)
at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:157)
... 40 more
Caused by: java.lang.NullPointerException
at org.drools.common.ConcurrentNodeMemories.getNodeMemory(ConcurrentNodeMemories.java:65)
at org.drools.common.AbstractWorkingMemory.getNodeMemory(AbstractWorkingMemory.java:1035)
at org.drools.marshalling.impl.InputMarshaller.readFactHandles(InputMarshaller.java:327)
at org.drools.marshalling.impl.InputMarshaller.readSession(InputMarshaller.java:221)
at org.drools.marshalling.impl.DefaultMarshaller.unmarshall(DefaultMarshaller.java:92)
at org.drools.persistence.SessionMarshallingHelper.loadSnapshot(SessionMarshallingHelper.java:91)
... 42 more
Thanks,
Demian