Stan is having problems opening XLS files due to an error message from the "Trust Center." It'll open the file, but he can't write back to it or save it to his hard drive. Leo says that is Microsoft's security center for excel spreadsheets because it's possible for bad actors to embed commands into an Excel file. There is a workaround for this. Stan can enable all content in the Excel Trust Center settings. But that can be risky if he's unsure of the content in the file he's opening. If he's sure about it, then he'll be OK.