RPE-01038: Failed to evaluate expression null.

Question

Hi, gurus! :)
Upon executing a process flow, I got the following error message:
RPE-01003: An infrastructure condition prevented the request from completing.
RPE-01038: Failed to evaluate expression null.  Please modify the expression, redeploy and retry again.
RPE-01003: An infrastructure condition prevented the request from completing.
RPE-02227: Cannot test Control Center user OWF_MGR. This user must match the login credentials of the evaluation location configured on owning module.
RPE-01003: An infrastructure condition prevented the request from completing.
java.lang.NullPointerException
I suspect I got this error from improper use of parameters (just started using). I've searched for answers in the internet, still I am not sure how to efficiently and correctly use parameters. I'm dealing with this "literal" confusion. I would like to confirm the following:
1. If a local parameter is an integer, how should I set the value and literal field? (say, set value to 0, literal = true?)
2. How about for while loops? The condition is automatically a string. If I use the paramater par_loc, how should I write it (say, par_loc < 100).
3. For Assign operators, data type is also an automatic string. What if I want to have an integer value? Or maybe an integer value thru an expression? (e.g. par_loc + 20).
The questions above somehow summarize the activity I created.
I'll try to do more tests and research and give you an update if I found any solution.
Any help will be deeply appreciated. Thank you, gurus!
Manoy :)

Answer 1

Thanks, Carsten! :)
I applied what you suggested. I still got the same error.
1. Defined the parameter via local variable --> same error as above
2. Defined it under start activity --> got a new error:
RPE-02075: Oracle Workflow failed to process the execution request for Activity PF_WHILE:WHILE_LOOP. This may be because dependent objects have not yet been deployed.
ORA-20007: The execution cannot be activated because not all required parameters have been set
WB_RT_WORKFLOW_UTIL_10G.Execute_Any_Task(PKG_WL, WB_IK_20090327_083358_51724, 12463, RUN)
WB_RT_WORKFLOW_UTIL_10G.Execute_Task(PKG_WL, WB_IK_20090327_083358_51724, 12463, RUN)
Wf_Engine_Util.Function_Call(WB_RT_WORKFLOW_UTIL_10G.EXECUTE_TASK, PKG_WL, WB_IK_20090327_083358_51724, 12463, RUN)
RPE-02083: Process PF_WHILE has errored Activities. Dependent objects may not have been deployed. You can use Oracle Workflow Monitor to retry the activities or abort the Process
Did I miss something? :|
Manoy