Request Reply in Process Model (Modeler)

I have created a Process Model that subscribes to a document and then run some steps. In the end I want the model to Reply to the caller with a new document.

So if I put pub.reply in the subscribing flow, everything works fine.

if I put the pub.reply in the End flow of the process i get the following error.

The Model is something like this.

This does work

Step1
Subscripe to document A.
Reply with document B.

Step2.
Nothing specific.

This does not work:

Step1
Subscripe to document A.
Step2.
Reply with Document B.

The error in Step 2 is.

com.wm.app.b2b.server.ServiceException: [ISS.0098.9010] No waiting thread for Document Id: 24f15de3b31f6860f68d2f8064. Requestor might have timed out. at pub.publish.reply(publish.java:76) at java.lang.reflect.Method.invoke(Native Method) at com.wm.app.b2b.server.JavaService.baseInvoke(JavaService.java(Compiled Code)) at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java(Compiled Code)) at com.wm.app.b2b.server.BaseService.invoke(BaseService.java(Compiled Code)) at com.wm.lang.flow.FlowInvoke.invoke(FlowInvoke.java(Compiled Code)) at com.wm.lang.flow.FlowState.invokeNode(FlowState.java(Compiled Code)) at com.wm.lang.flow.FlowState.invoke(FlowState.java(Compiled Code)) at com.wm.lang.flow.FlowState.invoke(FlowState.java(Compiled Code)) at com.wm.app.b2b.server.FlowSvcImpl.baseInvoke(FlowSvcImpl.java(Compiled Code)) at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java(Compiled Code)) at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java(Compiled Code)) at com.wm.app.b2b.server.Service.doInvoke(Service.java(Compiled Code)) at com.wm.app.b2b.server.Service.doInvoke(Service.java:554) at com.wm.app.prt.IntegrationServer.invoke(IntegrationServer.java:55) at com.wm.app.prt.IntegrationServer.invokeWrapper(IntegrationServer.java:41) at com.wm.app.prt.StepDispatcherAgent.runStep(StepDispatcherAgent.java:456) at com.wm.app.prt.StepDispatcherAgent.execute(StepDispatcherAgent.java:365) at com.wm.app.prt.StepDispatcherAgent.synchRun(StepDispatcherAgent.java:75) at com.wm.app.prt.StepDispatcher.startStep(StepDispatcher.java:490) at com.wm.app.prt.StepDispatcher.dispatch(StepDispatcher.java:455) at com.wm.app.prt.StepDispatcher.handleTransition(StepDispatcher.java:72) at wm.prt.dispatch.handleTransition(dispatch.java:64) at java.lang.reflect.Method.invoke(Native Method) at com.wm.app.b2b.server.JavaService.baseInvoke(JavaService.java(Compiled Code)) at com.wm.app.b2b.server.invoke.InvokeManag