Why does QuickBooks Error 15215 occur?
https://quickbookhelpdesk.com/blog/quickbooks-error-15215-explained-2/
The error may be caused by an unstable internet connection, security software interference, permission issues, background applications, outdated software, or temporary system glitches. QuickBooks Error 15215 typically occurs when the software cannot complete an update because of internet connectivity issues, background application conflicts, insufficient permissions, security software interference, or temporary system problems. Fortunately, the error can usually be resolved through careful troubleshooting and routine maintenance.