Error Message Debugging

Hello

I'm quite new to ABAP debug and there is a question in my mind.

For example, if I call transaction VF01 to create a billing document but it ends up with a message -

No billing documents were generated. See log

Message no. VF032

I can find this message in New Debugger. But the problem is that this information message doesn't really tell what exactly is wrong.

Then I follow the message to look into Log and find another message -

Error Log

            0080001234 000000 Document is incomplete so billing cannot be carried out

           Technical data

               Tech. data details

                Client                                 200
                Group Number
                Sales Document Number                  0080001234
                Item Number of the SD Document         000000
                Schedule Line Number                   0069
                Counter in Control Tables              00
                Message Identification                 VF
                System Message Number                  069
                Output Type                            E
                Message Variable 01
                Message Variable 02
                Message Variable 03
                Message Variable 04
                Group Type                             F

OK now I know the actual error is VF069 however I cannot set a breakpoint for this VF069 because the program doesn't seem to go there. For this kind of "hidden" error message how can I make my debug efficient?

yu