Why does Error 6123 appear when restoring a backup?

https://quickbookhelpdesk.com/blog/fix-quickbooks-error-6123/

The error can occur when QuickBooks has trouble accessing or restoring the backup. Moving the backup to the local hard drive and restoring it from there can help. QuickBooks Error 6123 can prevent you from opening, upgrading, or restoring a company file. The cause may be related to the company file, network connection, QuickBooks processes, installation, or computer compatibility.