Fixing the "Outlook PST Export Unknown Error" can be frustrating, but there are several troubleshooting steps you can take to resolve this issue. This error often occurs when you are trying to export data from Microsoft Outlook to a PST (Personal Storage Table) file. To fix Outlook PST Export Unknown Error, you can use different ways. If you are still facing the error, then you need to backup your Outlook emails as a precaution. For that you can use the SysConverter for Outlook on your Windows OS system.