"import accumulator" in Business Central gives ClassNotFound exception

Using Java11,
Busienss Central 7.36
Kie Server (spring boot) 7.36

Kie Server drl file imports following class fine and builds
import accumulate com.healthpartners.api.gsusetup.func.EffectiveDateAccumulateFunction effectiveDateRange;

But business central 'Build' button click throws the following exception:

2020-06-03 09:39:41,739 DEBUG [org.kie.workbench.common.screens.server.management.backend.storage.ServerTemplateVFSStorage] (Thread-181) About to load all available server templates (as keys only)...
2020-06-03 09:39:41,752 DEBUG [org.kie.workbench.common.screens.server.management.backend.storage.ServerTemplateVFSStorage] (Thread-181) No directory found remote, returning empty result
2020-06-03 09:39:43,496 ERROR [org.kie.workbench.common.services.backend.builder.core.BuildHelper] (default task-5) Error loading accumulate function for identifier effectiveDateRange. Class com.healthpartners.api.gsusetup.func.EffectiveDateAccumulateFunction not found: java.lang.RuntimeException: Error loading accumulate function for identifier effectiveDateRange. Class com.healthpartners.api.gsusetup.func.EffectiveDateAccumulateFunction not found
at deployment.business-central.war//org.drools.compiler.builder.impl.KnowledgeBuilderImpl.loadAccumulateFunction(KnowledgeBuilderImpl.java:1707)
at deployment.business-central.war//org.drools.compiler.builder.impl.KnowledgeBuilderImpl.processAccumulateFunctions(KnowledgeBuilderImpl.java:1692)
at deployment.business-central.war//org.drools.compiler.builder.impl.KnowledgeBuilderImpl.processOtherDeclarations(KnowledgeBuilderImpl.java:1642)
at deployment.business-central.war//org.drools.compiler.builder.impl.KnowledgeBuilderImpl.buildOtherDeclarations(KnowledgeBuilderImpl.java:2491)
at deployment.business-central.war//org.drools.compiler.builder.impl.KnowledgeBuilderImpl.buildPackagesWithoutRules(KnowledgeBuilderImpl.java:2438)
at deployment.business-central.war//org.drools.compiler.builder.impl.KnowledgeBuilderImpl.buildPackages(KnowledgeBuilderImpl.java:2427)
at deployment.business-central.war//org.drools.compiler.builder.impl.CompositeKnowledgeBuilderImpl.build(CompositeKnowledgeBuilderImpl.java:106)
at deployment.business-central.war//org.drools.compiler.builder.impl.CompositeKnowledgeBuilderImpl.build(CompositeKnowledgeBuilderImpl.java:98)
at deployment.business-central.war//org.drools.compiler.kie.builder.impl.AbstractKieProject.buildKnowledgePackages(AbstractKieProject.java:261)
at deployment.business-central.war//org.drools.compiler.kie.builder.impl.AbstractKieProject.verify(AbstractKieProject.java:75)
at deployment.business-central.war//org.drools.compiler.kie.builder.impl.KieBuilderImpl.buildKieProject(KieBuilderImpl.java:274)
at deployment.business-central.war//org.drools.compiler.kie.builder.impl.KieBuilderImpl.buildAll(KieBuilderImpl.java:242)
at deployment.business-central.war//org.drools.compiler.kie.builder.impl.KieBuilderImpl.buildAll(KieBuilderImpl.java:199)
at deployment.business-central.war//org.drools.compiler.kie.builder.impl.KieBuilderImpl.getKieModule(KieBuilderImpl.java:505)
at deployment.business-central.war//org.drools.compiler.kie.builder.impl.KieBuilderImpl.getKieModule(KieBuilderImpl.java:515)
at deployment.business-central.war//org.drools.compiler.kie.builder.impl.KieBuilderImpl.getKieModuleIgnoringErrors(KieBuilderImpl.java:500)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.core.Builder.getKieModuleIgnoringErrors(Builder.java:578)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.core.Builder.build(Builder.java:264)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.core.BuildHelper.build(BuildHelper.java:92)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.core.BuildHelper$Proxy$_$$_WeldClientProxy.build(Unknown Source)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.ala.LocalBuildExecConfigExecutor.apply(LocalBuildExecConfigExecutor.java:61)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.ala.LocalBuildExecConfigExecutor.apply(LocalBuildExecConfigExecutor.java:32)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.ala.LocalBuildExecConfigExecutor$Proxy$_$$_WeldClientProxy.apply(Unknown Source)
at deployment.business-central.war//org.guvnor.ala.pipeline.execution.PipelineExecutor.lambda$continuePipeline$0(PipelineExecutor.java:109)
at deployment.business-central.war//org.guvnor.ala.pipeline.StageUtil$1.execute(StageUtil.java:38)
at deployment.business-central.war//org.guvnor.ala.pipeline.StageUtil$1.execute(StageUtil.java:33)
at deployment.business-central.war//org.guvnor.ala.pipeline.execution.PipelineExecutor.continuePipeline(PipelineExecutor.java:94)
at deployment.business-central.war//org.guvnor.ala.pipeline.execution.PipelineExecutor.execute(PipelineExecutor.java:76)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.ala.BuildPipelineInvoker.invokeLocalBuildPipeLine(BuildPipelineInvoker.java:88)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.ala.BuildPipelineInvoker$Proxy$_$$_WeldClientProxy.invokeLocalBuildPipeLine(Unknown Source)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.service.BuildServiceHelper.invokeLocalBuildPipeLine(BuildServiceHelper.java:152)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.service.BuildServiceHelper.localBuild(BuildServiceHelper.java:67)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.service.BuildServiceHelper$Proxy$_$$_WeldClientProxy.localBuild(Unknown Source)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.service.BuildServiceImpl.build(BuildServiceImpl.java:64)
at deployment.business-central.war//org.kie.workbench.common.services.backend.builder.service.BuildServiceImpl$Proxy$_$$_WeldClientProxy.build(Unknown Source)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at deployment.business-central.war//org.jboss.errai.bus.server.io.AbstractRPCMethodCallback.invokeMethodFromMessage(AbstractRPCMethodCallback.java:65)
at deployment.business-central.war//org.jboss.errai.bus.server.io.ValueReplyRPCEndpointCallback.callback(ValueReplyRPCEndpointCallback.java:40)
at deployment.business-central.war//org.jboss.errai.bus.server.io.RemoteServiceCallback.callback(RemoteServiceCallback.java:54)
at deployment.business-central.war//org.jboss.errai.cdi.server.CDIExtensionPoints$2.callback(CDIExtensionPoints.java:448)
at deployment.business-central.war//org.jboss.errai.bus.server.DeliveryPlan.deliver(DeliveryPlan.java:47)
at deployment.business-central.war//org.jboss.errai.bus.server.ServerMessageBusImpl.sendGlobal(ServerMessageBusImpl.java:297)
at deployment.business-central.war//org.jboss.errai.bus.server.SimpleDispatcher.dispatchGlobal(SimpleDispatcher.java:46)
at deployment.business-central.war//org.jboss.errai.bus.server.service.ErraiServiceImpl.store(ErraiServiceImpl.java:96)
at deployment.business-central.war//org.jboss.errai.bus.server.service.ErraiServiceImpl.store(ErraiServiceImpl.java:113)
at deployment.business-central.war//org.jboss.errai.bus.server.servlet.DefaultBlockingServlet.doPost(DefaultBlockingServlet.java:144)
at javax.servlet.api@1.0.0.Final//javax.servlet.http.HttpServlet.service(HttpServlet.java:706)
at javax.servlet.api@1.0.0.Final//javax.servlet.http.HttpServlet.service(HttpServlet.java:791)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
at io.undertow.websocket@2.0.13.Final//io.undertow.websockets.jsr.JsrWebSocketFilter.doFilter(JsrWebSocketFilter.java:173)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at deployment.business-central.war//org.uberfire.ext.security.server.SecureHeadersFilter.doFilter(SecureHeadersFilter.java:110)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at deployment.business-central.war//org.uberfire.ext.security.server.SecurityIntegrationFilter.doFilter(SecurityIntegrationFilter.java:70)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at io.opentracing.contrib.opentracing-jaxrs2//io.opentracing.contrib.jaxrs2.server.SpanFinishingFilter.doFilter(SpanFinishingFilter.java:55)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at org.wildfly.extension.undertow@14.0.1.Final//org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
at io.undertow.core@2.0.13.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:132)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
at io.undertow.core@2.0.13.Final//io.undertow.server.handlers.DisableCacheHandler.handleRequest(DisableCacheHandler.java:33)
at io.undertow.core@2.0.13.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.core@2.0.13.Final//io.undertow.security.handlers.AuthenticationConstraintHandler.handleRequest(AuthenticationConstraintHandler.java:53)
at io.undertow.core@2.0.13.Final//io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.security.ServletSecurityConstraintHandler.handleRequest(ServletSecurityConstraintHandler.java:59)
at io.undertow.core@2.0.13.Final//io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
at io.undertow.core@2.0.13.Final//io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
at io.undertow.core@2.0.13.Final//io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
at io.undertow.core@2.0.13.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at org.wildfly.extension.undertow@14.0.1.Final//org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
at io.undertow.core@2.0.13.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at org.wildfly.extension.undertow@14.0.1.Final//org.wildfly.extension.undertow.deployment.GlobalRequestControllerHandler.handleRequest(GlobalRequestControllerHandler.java:68)
at io.undertow.core@2.0.13.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:292)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
at org.wildfly.extension.undertow@14.0.1.Final//org.wildfly.extension.undertow.security.SecurityContextThreadSetupAction.lambda$create$0(SecurityContextThreadSetupAction.java:105)
at org.wildfly.extension.undertow@14.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502)
at org.wildfly.extension.undertow@14.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502)
at org.wildfly.extension.undertow@14.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502)
at org.wildfly.extension.undertow@14.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
at io.undertow.servlet@2.0.13.Final//io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104)
at io.undertow.core@2.0.13.Final//io.undertow.server.Connectors.executeRootHandler(Connectors.java:360)
at io.undertow.core@2.0.13.Final//io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830)
at org.jboss.threads@2.3.2.Final//org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
at org.jboss.threads@2.3.2.Final//org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1985)
at org.jboss.threads@2.3.2.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1487)
at org.jboss.threads@2.3.2.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1378)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.ClassNotFoundException: Unable to find class 'com.healthpartners.api.gsusetup.func.EffectiveDateAccumulateFunction'
at deployment.business-central.war//org.drools.core.addon.ClassTypeResolver.resolveType(ClassTypeResolver.java:268)
at deployment.business-central.war//org.drools.core.addon.ClassTypeResolver.resolveType(ClassTypeResolver.java:153)
at deployment.business-central.war//org.drools.compiler.builder.impl.KnowledgeBuilderImpl.loadAccumulateFunction(KnowledgeBuilderImpl.java:1704)
... 108 more