We have implemented a custom authentication for Mashup. If the authentication fails, we don't want to present default log on screen, so just coded a html stream and referred it in the auth activity's failure step. But the activity fails with the exception given below.

Also, attached screenshots of auth service and auth activity's steps. Can anyone help ? thanks!

2017-03-06 10:20:35,050 [ WebContainer : 13] [ STANDARD] [ App:05.02.01] (ngineinterface.service.HttpAPI) ERROR xxxx|xxxx: com.pega.pegarules.pub.PRRuntimeException
com.pega.pegarules.pub.PRRuntimeException: No failure response set by custom authentication activity
at com.pega.pegarules.session.internal.mgmt.authentication.SchemePRCustom.onAuthenticationFailure(SchemePRCustom.java:956)
at com.pega.pegarules.session.internal.mgmt.authentication.Authentication.doAuthentication(Authentication.java:630)
at com.pega.pegarules.session.internal.engineinterface.service.HttpAPI.handleAuthentication(HttpAPI.java:2234)
at com.pega.pegarules.session.external.engineinterface.service.EngineAPI.activityExecutionProlog(EngineAPI.java:548)
at com.pega.pegarules.session.external.engineinterface.service.EngineAPI.processRequestInner(EngineAPI.java:383)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:60)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
at java.lang.reflect.Method.invoke(Method.java:611)
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:850)
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.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:60)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
at java.lang.reflect.Method.invoke(Method.java:611)
at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethod(PRBootstrap.java:367)
at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethodPropagatingThrowable(PRBootstrap.java:408)
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 com.pega.pegarules.internal.etier.interfaces.EJSLocalStatelessEngineBMT_f2439d86.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.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:60)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
at java.lang.reflect.Method.invoke(Method.java:611)
at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethod(PRBootstrap.java:367)
at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethodPropagatingThrowable(PRBootstrap.java:408)
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 javax.servlet.http.HttpServlet.service(HttpServlet.java:738)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:831)
at com.ibm.ws.cache.servlet.ServletWrapper.serviceProxied(ServletWrapper.java:307)
at com.ibm.ws.cache.servlet.CacheHook.handleFragment(CacheHook.java:576)
at com.ibm.ws.cache.servlet.CacheHook.handleServlet(CacheHook.java:250)
at com.ibm.ws.cache.servlet.ServletWrapper.service(ServletWrapper.java:259)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1694)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:970)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:508)
at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:181)
at com.ibm.ws.webcontainer.servlet.CacheServletWrapper.handleRequest(CacheServletWrapper.java:91)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:878)
at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1592)
at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:191)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:454)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:516)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:307)
at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:84)
at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:175)
at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1662)

Pega version: 7.1.8, No gateway in IAC configuration.