Spring Webflow: cannot get flow execution url at action phase of portlet

The following exception is thrown:

Caused by: java.lang.IllegalStateException: A flow execution action URL can only be obtained in a RenderRequest using a 
RenderResponse
    at org.springframework.webflow.context.portlet.PortletExternalContext.getFlowExecutionUrl(PortletExternalContext.java:2
06)
    at org.springframework.webflow.engine.impl.RequestControlContextImpl.getFlowExecutionUrl(RequestControlContextImpl.java
:178)
    at org.springfram开发者_JAVA百科ework.webflow.mvc.view.AbstractMvcView.render(AbstractMvcView.java:172)
    at org.springframework.webflow.engine.ViewState.render(ViewState.java:282)
    at org.springframework.webflow.engine.ViewState.refresh(ViewState.java:241)
    at org.springframework.webflow.engine.ViewState.resume(ViewState.java:219)
    at org.springframework.webflow.engine.Flow.resume(Flow.java:545)
    at org.springframework.webflow.engine.impl.FlowExecutionImpl.resume(FlowExecutionImpl.java:259)
    ... 62 more

It seems for me like resuming execution of flow at action phase tries to do render phase's stuff. Any ideas?

---

The error was in not provding eventId in request because of syntax error.