WLP Struts DownloadAction handleNullActionResult exception

[N Ha]

Hello,

I'm trying to download a resource from within a portlet using Struts DownloadAction but I get the following exception
Caused By: com.bea.portlet.adapter.scopedcontent.ActionLookupFailedException
at com.bea.portlet.adapter.scopedcontent.StrutsStubImpl.handleNullActionResult(StrutsStubImpl.java:148)
at com.bea.portlet.adapter.scopedcontent.ScopedContentCommonSupport.executeAction(ScopedContentCommonSupport.java:766)
at com.bea.portlet.adapter.scopedcontent.ScopedContentCommonSupport.processActionInternal(ScopedContentCommonSupport.java:141)
at com.bea.portlet.adapter.scopedcontent.StrutsStubImpl.processAction(StrutsStubImpl.java:72)
at com.bea.portlet.adapter.NetuiActionHandler.raiseScopedAction(NetuiActionHandler.java:111)

I guess that's because the Download Action returns a StreamInfo whereas the portal does not allow that.

I'm using WebLogic Portal 10.3.2 and Struts 1.2

Any help?