https://www.theverge.com/2018/12/18/18146134/microsoft-windows-10-october-2018-update-available-all-pcs-download

Microsoft has resolved a number of blocking bugs that prevented some Windows 10 users from installing the latest October 2018 Update. The software giant originally re-released this update last month, following some file deletion issues after its original release in October. Microsoft has since been working on ensuring all PCs can get the update, after blocking it on some systems that had incompatible software or hardware drivers.

Some of those blocking bugs included compatibility issues with iCloud, VPN clients, and Trend Micro’s security software. Microsoft has been very transparent in detailing all of the issues over at the company’s support site, and it has now noted that Windows 10 October 2018 Update “is now fully available for advanced users who manually select ‘Check for updates’ via Windows Update.” That means you should be able to check for updates on any PC now and get the October 2018 update reliably.