Hi All -  I am getting this error on UI when I try to open a particular activity rule "There has been an issue; please consult your system administrator.".

After tracing I can see error message in tracer - "The reference .pyDelegationsForRuleType(@baseclass) is not valid.  Reason: unexpected character '@' at position 26, expected subscript " and below stack trace(looks like property set for pyDelegationsForRuleType is throwing exception at step 12 in OOTB activity named wbtoolbarddsettings). can someone please help me understand and resolve the issue?

at position 26, expected subscript at com.pega.pegarules.data.internal.clipboard.PropertyReferenceImpl.initialize(PropertyReferenceImpl.java:3013) 
 at com.pega.pegarules.data.internal.clipboard.PropertyReferencePoolImpl.get(PropertyReferencePoolImpl.java:99) 
 at com.pega.pegarules.data.internal.clipboard.PropertyReferenceImpl.subReference(PropertyReferenceImpl.java:3625) 
 at com.pega.pegarules.data.internal.clipboard.PropertyReferenceImpl.removeLastProperty(PropertyReferenceImpl.java:2800) 
 at com.pega.pegarules.data.internal.clipboard.PropertyReferenceImpl.initialize(PropertyReferenceImpl.java:3198) 
 at com.pega.pegarules.data.internal.clipboard.PropertyReferencePoolImpl.get(PropertyReferencePoolImpl.java:122) 
 at com.pega.pegarules.data.internal.clipboard.PropertyReferencePoolImpl$StaticHelper.get(PropertyReferencePoolImpl.java:165) 
 at com.pega.pegarules.data.external.clipboard.PropertyReferencePool.get(PropertyReferencePool.java:62) 
 at com.pega.pegarules.session.internal.mgmt.Executable.getAnyValueViaPropRef(Executable.java:10046) 
 at com.pega.pegarules.session.internal.mgmt.Executable.getStringValueViaPropRef(Executable.java:10191) 
 at com.pegarules.generated.activity.ra_action_wbtoolbarddsettings_9a469343ff55b48369ec8575895d72dc.step12_circum0(ra_action_wbtoolbarddsettings_9a469343ff55b48369ec8575895d72dc.java:1386) 
 at com.pegarules.generated.activity.ra_action_wbtoolbarddsettings_9a469343ff55b48369ec8575895d72dc.perform(ra_action_wbtoolbarddsettings_9a469343ff55b48369ec8575895d72dc.java:258) 
 at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3505) 
 at com.pega.pegarules.session.internal.mgmt.Executable.invokeActivity(Executable.java:10563) 
 at com.pegarules.generated.activity.ra_action_onbeforedisplay_73be703c71638484f9e536ae97ee89b6.step2_circum0(ra_action_onbeforedisplay_73be703c71638484f9e536ae97ee89b6.java:506) 
 at com.pegarules.generated.activity.ra_action_onbeforedisplay_73be703c71638484f9e536ae97ee89b6.perform(ra_action_onbeforedisplay_73be703c71638484f9e536ae97ee89b6.java:86) 
 at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3505) 
 at com.pega.pegarules.session.internal.mgmt.Executable.invokeActivity(Executable.java:10563) 
 at com.pegarules.generated.activity.ra_action_onbeforedisplay_970311e1ab8e808acdf904d20bf2d5fe.step3_1_circum0(ra_action_onbeforedisplay_970311e1ab8e808acdf904d20bf2d5fe.java:514) 
 at com.pegarules.generated.activity.ra_action_onbeforedisplay_970311e1ab8e808acdf904d20bf2d5fe.step3_0_circum0(ra_action_onbeforedisplay_970311e1ab8e808acdf904d20bf2d5fe.java:336) 
 at com.pegarules.generated.activity.ra_action_onbeforedisplay_970311e1ab8e808acdf904d20bf2d5fe.perform(ra_action_onbeforedisplay_970311e1ab8e808acdf904d20bf2d5fe.java:123) 
 at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3505) 
 at com.pega.pegarules.session.internal.mgmt.Executable.invokeActivity(Executable.java:10563) 
 at com.pegarules.generated.activity.ra_action_wbopen_636ddc8d3c8d3933fb470ef82428b1d6.step24_circum0(ra_action_wbopen_636ddc8d3c8d3933fb470ef82428b1d6.java:2225) 
 at com.pegarules.generated.activity.ra_action_wbopen_636ddc8d3c8d3933fb470ef82428b1d6.perform(ra_action_wbopen_636ddc8d3c8d3933fb470ef82428b1d6.java:537) 
 at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3505) 
 at com.pega.pegarules.session.internal.mgmt.Executable.invokeActivity(Executable.java:10563) 
 at com.pegarules.generated.activity.ra_action_douiaction_e7228a040c3bf89efe31545c6149a3d4.step28_circum0(ra_action_douiaction_e7228a040c3bf89efe31545c6149a3d4.java:2860) 
 at com.pegarules.generated.activity.ra_action_douiaction_e7228a040c3bf89efe31545c6149a3d4.perform(ra_action_douiaction_e7228a040c3bf89efe31545c6149a3d4.java:526) 
 at com.pega.pegarules.session.internal.mgmt.Executable.doActivity(Executable.java:3505) 
 at com.pega.pegarules.session.internal.mgmt.base.ThreadRunner.runActivitiesAlt(ThreadRunner.java:646) 
 at com.pega.pegarules.session.internal.mgmt.PRThreadImpl.runActivitiesAlt(PRThreadImpl.java:461) 
 at com.pega.pegarules.session.internal.engineinterface.service.HttpAPI.runActivities(HttpAPI.java:3358) 
 at com.pega.pegarules.session.external.engineinterface.service.EngineAPI.processRequestInner(EngineAPI.java:385) 
 at sun.reflect.GeneratedMethodAccessor235.invoke(Unknown Source) 
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
 at java.lang.reflect.Method.invoke(Method.java:606) 
 at com.pega.pegarules.session.internal.PRSessionProviderImpl.performTargetActionWithLock(PRSessionProviderImpl.java:1270) 
 at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:1008) 
 at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:841) 
 at com.pega.pegarules.session.external.engineinterface.service.EngineAPI.processRequest(EngineAPI.java:331) 
 at com.pega.pegarules.session.internal.engineinterface.service.HttpAPI.invoke(HttpAPI.java:852) 
 at com.pega.pegarules.session.internal.engineinterface.etier.impl.EngineImpl._invokeEngine_privact(EngineImpl.java:315) 
 at com.pega.pegarules.session.internal.engineinterface.etier.impl.EngineImpl.invokeEngine(EngineImpl.java:263) 
 at com.pega.pegarules.session.internal.engineinterface.etier.ejb.EngineBean.invokeEngine(EngineBean.java:225) 
 at sun.reflect.GeneratedMethodAccessor223.invoke(Unknown Source) 
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
 at java.lang.reflect.Method.invoke(Method.java:606) 
 at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethod(PRBootstrap.java:370) 
 at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethodPropagatingThrowable(PRBootstrap.java:411) 
 at com.pega.pegarules.boot.internal.extbridge.AppServerBridgeToPega.invokeMethodPropagatingThrowable(AppServerBridgeToPega.java:223) 
 at com.pega.pegarules.boot.internal.extbridge.AppServerBridgeToPega.invokeMethodPropagatingException(AppServerBridgeToPega.java:245) 
 at com.pega.pegarules.internal.etier.ejb.EngineBeanBoot.invokeEngine(EngineBeanBoot.java:168) 
 at sun.reflect.GeneratedMethodAccessor222.invoke(Unknown Source) 
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
 at java.lang.reflect.Method.invoke(Method.java:606) 
 at com.bea.core.repackaged.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:310) 
 at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182) 
 at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149) 
 at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131) 
 at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119) 
 at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) 
 at com.oracle.pitchfork.spi.MethodInvocationVisitorImpl.visit(MethodInvocationVisitorImpl.java:34) 
 at weblogic.ejb.container.injection.EnvironmentInterceptorCallbackImpl.callback(EnvironmentInterceptorCallbackImpl.java:54) 
 at com.oracle.pitchfork.spi.EnvironmentInterceptor.invoke(EnvironmentInterceptor.java:42) 
 at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) 
 at com.bea.core.repackaged.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89) 
 at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) 
 at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131) 
 at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119) 
 at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) 
 at com.bea.core.repackaged.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) 
 at com.sun.proxy.$Proxy56.invokeEngine(Unknown Source) 
 at com.pega.pegarules.internal.etier.ejb.EngineBMT_h449u3_ELOImpl.__WL_invoke(Unknown Source) 
 at weblogic.ejb.container.internal.SessionLocalMethodInvoker.invoke(SessionLocalMethodInvoker.java:39) 
 at com.pega.pegarules.internal.etier.ejb.EngineBMT_h449u3_ELOImpl.invokeEngine(Unknown Source) 
 at com.pega.pegarules.priv.context.JNDIEnvironment.invokeEngineInner(JNDIEnvironment.java:278) 
 at com.pega.pegarules.priv.context.JNDIEnvironment.invokeEngine(JNDIEnvironment.java:223) 
 at com.pega.pegarules.web.impl.WebStandardImpl.makeEtierRequest(WebStandardImpl.java:574) 
 at com.pega.pegarules.web.impl.WebStandardImpl.doPost(WebStandardImpl.java:374) 
 at sun.reflect.GeneratedMethodAccessor233.invoke(Unknown Source) 
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
 at java.lang.reflect.Method.invoke(Method.java:606) 
 at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethod(PRBootstrap.java:370) 
 at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethodPropagatingThrowable(PRBootstrap.java:411) 
 at com.pega.pegarules.boot.internal.extbridge.AppServerBridgeToPega.invokeMethodPropagatingThrowable(AppServerBridgeToPega.java:223) 
 at com.pega.pegarules.boot.internal.extbridge.AppServerBridgeToPega.invokeMethod(AppServerBridgeToPega.java:272) 
 at com.pega.pegarules.internal.web.servlet.WebStandardBoot.doPost(WebStandardBoot.java:121) 
 at com.pega.pegarules.internal.web.servlet.WebStandardBoot.doGet(WebStandardBoot.java:92) 
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) 
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) 
 at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227) 
 at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125) 
 at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:301) 
 at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:184) 
 at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3750) 
 at ...