Hi Sam,
While I am no expert on this, I have seen this situation before. Basically, it means that the production order has an item that has a predefined budget assigned to it. This error is generated when the budget is consumed. It is a production order or material related issue and needs to be looked at functionally. I think CJ31 is the tcode to check budgets but not sure how much you can do there.
To answer your questions, it is a system generated error and I do not think it can be turned into a warning. Regarding you going through with your code, I should not comment on that as I do not know exactly what you are working on. However, since this is most likely a production order related issue, you can possibly go ahead with your coding unless you have triggered this error by your code in the first place.
Thanks,
Soumyajit