How to solve QuickBooks Error 15215?

https://quickbookhelpdesk.com/blog/quickbooks-error-15215-explained/

QuickBooks Error 15215 usually occurs when updating QuickBooks Desktop or downloading payroll updates. It is often caused by conflicts with background applications, firewall restrictions, or unstable internet settings that prevent secure communication with Intuit's servers. Users may see an error message and interrupted updates. Common fixes include restarting the computer, running QuickBooks as an administrator, verifying internet and firewall settings, and ensuring no other programs are blocking the update process.