Update problems are caused by QuickBooks Error Code 15243 when the QuickBooks File Copy Service (FCS) is deactivated or not operating properly. Usually, this issue happens when updating software or processing payroll. It can be fixed by manually downloading updates to restore functionality, fixing the QuickBooks installation, or turning on the FCS service. Call 1.855.738.2784 to speak with the QB Support staff if you run into any issues.