Microsoft has pulled Windows 10 version 1809 from Windows Update (and other places) to allow engineers time to fix a widely reported issue of missing documents after the in place upgrade. They announced this in the following post:
We have paused the rollout of the Windows 10 October 2018 Update (version 1809)* for all users as we investigate isolated reports of users missing some files after updating.
If you have manually downloaded the Windows 10 October 2018 Update installation media, please don’t install it and wait until new media is available.
We will provide an update when we resume rolling out the Windows 10 October 2018 Update to customers.
I’ll update this when Windows 10 version 1809 is available again but for now the advice is don’t deploy it until a fix is made available