Drools implicitly requires ReleaseIdImpl in its implementation for loading a kjar. Any classes implementing ReleaseId will cause ClassCastExceptions during load:

Caused by: java.lang.ClassCastException: org.jbpm.ee.support.KieReleaseId cannot be cast to org.drools.compiler.kproject.ReleaseIdImpl
at org.drools.compiler.kie.builder.impl.KieBuilderImpl.getCompilationCachePath(KieBuilderImpl.java:289) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.AbstractKieModule.getCompilationCache(AbstractKieModule.java:300) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.AbstractKieModule.buildKnowledgePackages(AbstractKieModule.java:164) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.AbstractKieProject.verify(AbstractKieProject.java:39) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.KieBuilderImpl.buildKieProject(KieBuilderImpl.java:305) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.KieBuilderImpl.buildKieModule(KieBuilderImpl.java:300) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.kie.scanner.KieRepositoryScannerImpl.build(KieRepositoryScannerImpl.java:164) [kie-ci-6.0.0.CR4.jar:6.0.0.CR4]
at org.kie.scanner.KieRepositoryScannerImpl.buildArtifact(KieRepositoryScannerImpl.java:119) [kie-ci-6.0.0.CR4.jar:6.0.0.CR4]
at org.kie.scanner.KieRepositoryScannerImpl.loadArtifact(KieRepositoryScannerImpl.java:89) [kie-ci-6.0.0.CR4.jar:6.0.0.CR4]
at org.kie.scanner.KieRepositoryScannerImpl.loadArtifact(KieRepositoryScannerImpl.java:82) [kie-ci-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.KieRepositoryImpl.loadKieModuleFromMavenRepo(KieRepositoryImpl.java:109) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.KieRepositoryImpl.getKieModule(KieRepositoryImpl.java:95) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.KieRepositoryImpl.getKieModule(KieRepositoryImpl.java:76) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.drools.compiler.kie.builder.impl.KieServicesImpl.newKieContainer(KieServicesImpl.java:82) [drools-compiler-6.0.0.CR4.jar:6.0.0.CR4]
at org.jbpm.ee.startup.KnowledgeManagerBean.getKieContainer(KnowledgeManagerBean.java:61) [test-jbpm-services.jar:]
at org.jbpm.ee.startup.KnowledgeManagerBean.getKieBase(KnowledgeManagerBean.java:74) [test-jbpm-services.jar:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_25]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_25]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_25]
at java.lang.reflect.Method.invoke(Method.java:606) [rt.jar:1.7.0_25]
at org.jboss.as.ee.component.ManagedReferenceMethodInterceptorFactory$ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptorFactory.java:72) [jboss-as-ee-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.invocation.WeavedInterceptor.processInvocation(WeavedInterceptor.java:53) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:58) [jboss-as-ee-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:374) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.doMethodInterception(Jsr299BindingsInterceptor.java:129) [jboss-as-weld-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.processInvocation(Jsr299BindingsInterceptor.java:137) [jboss-as-weld-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:58) [jboss-as-ee-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.invocation.WeavedInterceptor.processInvocation(WeavedInterceptor.java:53) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:58) [jboss-as-ee-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.ejb3.component.invocationmetrics.ExecutionTimeInterceptor.processInvocation(ExecutionTimeInterceptor.java:43) [jboss-as-ejb3-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:374) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.ejb3.concurrency.ContainerManagedConcurrencyInterceptor.processInvocation(ContainerManagedConcurrencyInterceptor.java:104) [jboss-as-ejb3-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.weld.ejb.EjbRequestScopeActivationInterceptor.processInvocation(EjbRequestScopeActivationInterceptor.java:74) [jboss-as-weld-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.invocation.InitialInterceptor.processInvocation(InitialInterceptor.java:21) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.ee.component.interceptors.ComponentDispatcherInterceptor.processInvocation(ComponentDispatcherInterceptor.java:53) [jboss-as-ee-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.ejb3.component.singleton.SingletonComponentInstanceAssociationInterceptor.processInvocation(SingletonComponentInstanceAssociationInterceptor.java:52) [jboss-as-ejb3-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.2.Final-redhat-1.jar:1.1.2.Final-redhat-1]
at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInCallerTx(CMTTxInterceptor.java:226) [jboss-as-ejb3-7.2.1.Final-redhat-10.jar:7.2.1.Final-redhat-10]
... 186 more