Is there a way to disable automatic build updates in Windows 10? Or a way so the automatic update does not update to build 1809? We have some SaaS applications that error on build 1809 with the IE 11 update that comes with it.
Generally, no, you cannot reliably disable those updates. However, depending on the Windows 10 version you have (not possible with home), you may defer feature updates up to one year and just skip 1809, hoping for your issue to get fixed in newer releases. Read https://www.ghacks.net/2018/09/27/how-to-delay-feature-updates-in-windows-10/ for more information on that. The only reliable and supported way of not getting feature updates, ever, would be moving the affected machines to run Windows 10 Enterprise 2016 LTSC. This platform will receive only security updates until it reaches end of support on Oct. 13, 2026. However, this comes with licensing (you'll need an Enterprise licensing agreement with Microsoft) and usability (Microsoft doesn't want you using LTSC builds on regular 'information worker' machines) issues.