Failed to upgrade SharePoint Products.
This is a critical task. You have to fix the failures before you can continue. Follow this link for more information about how to troubleshoot upgrade failures:
An exception of type Microsoft.SharePoint.PostSetupConfiguration.PostSetupConfigurationTaskException was thrown. Additional exception information: Upgrade [SPContentDatabase Name=WSS_Content] failed. (EventID:an59t) Exception: The upgraded database schema doesn't match the TargetSchema (EventID:an59t) Upgrade Timer job is exiting due to exception: Microsoft.SharePoint.Upgrade.SPUpgradeException: The upgraded database schema doesn't match the TargetSchema
1. Use the following PowerShell script to upgrade all content databases:
Get-SPContentDatabase | Upgrade-SPContentDatabase -Confirm:$false
2. Run SharePoint Products Configuration Wizard again