Error in Webflow - launch handler URL !

[Venkat S Raman]

We are on EBP 3.5 on WAS 6.2 and are trying to implement the Webflow
delivered as part of WAS 6.2 with the package SWX.
 
We are using the business object TRAVELREQ and the workflow step in
question is the step Book a Flight that pops up the BSP with the possible
flighst (input parameters are cityin, cityout, outdate, returndate).
 
When the user tries to execute the Worflow item within Workplace  we get
the following error:
 
Work item 000000528659: Object object method SWW_WW_EXECUTE_S cannot be
executed
 
When I look into the Workflow log the real problem is the following
message:
  Error when creating the launch handler URL!
 
As far as I know I have everything setup( we created the service with
WF_EXTSRV and also ran the WF_HANDCUST.
 
Is there any documentation somewhere on this problem - oss is of no help
here.
 
Thanks
 
Venkat