I'm getting stuck on this paragraph, it seems that it's missing a 'locks','stops working' or something else: "If a customer comes to you and says that occasion

I'm getting stuck on this paragraph, it seems that it's missing a 'locks','stops working' or something else: "If a customer comes to you and says that occasionally when they click the "run business" button on the application you built for them, how do you go about solving the problem?"