It appears that oracle warehouse builder (OWB) will tell you have an error even though there is no error. Case in point, while creating a process flow, I had a Stored Procedure from a package returning back a Boolean value. I use this return value to determine the transition to the next activity as seen in figure 1.
I set the complex condition "PFUNC_RACS_AVAILABLE"."P_BAVAILABLE" for end with success. I then set the end with errors with NOT "PFUNC_RACS_AVAILABLE"."P_BAVAILABLE" . Finally I set no condition for end with warnings. But when I did a validation on the condition, OWB said I had an error in the expression (figure2). The error was PLS-00530: Illegal type used for object.
Now since I have been working in OWB for a while, I have learned oracle not only gives bad error messages, but incorrect ones as well. Therefore I question most messages from Oracle and decided to test the process flow to make sure. In the figure below, the test shows the flow did work correctly. The second test I simply reversed the conditions between success and errors.
As another test I checked the results in the control center to see what was returned from the procedure. Sure enough, a Boolean value was returned. I even reversed what was return to make sure I would be getting a false value (see figure 4).