Invoke operation not found

Hi all,

I have a problem invoking a small process inside a bigger process. I get the following error:
2007-12-10 14:38:00,206 ERROR [com.adobe.workflow.AWS] stalling action-instance: 4545 with message: ALC-DSC-121-000: com.adobe.idp.dsc.registry.InputParameterNotFoundException: Operation: invoke not found on service: Send mails to receiver
at com.adobe.idp.dsc.registry.infomodel.impl.OperationImpl.getInputParam eter(OperationImpl.java:175)
at com.adobe.workflow.engine.PEUtil.invokeAction(PEUtil.java:480)
at com.adobe.workflow.engine.ProcessEngineBMTBean.continueBranchAtAction (ProcessEngineBMTBean.java:2881)
at com.adobe.workflow.engine.ProcessEngineBMTBean.asyncContinueBranchCom mand(ProcessEngineBMTBean.java:2380)
at sun.reflect.GeneratedMethodAccessor898.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)

I can understand the error, but I don't know what I can do to fix the problem. The process is activated and I have set invoke permissions to the process creator. However I still get this error.

Hope you can help.

Sincerely
Kim Christensen