On Friday Microsoft released build 18362 of Windows 10 19H1, for the first time in this development bringing the slow ring into line with the fast ring. It seems many insiders, including me are having trouble with the build failing to install. It looks like the problem is with 18356.15 cumulative update which is preventing 18362 from installing. Microsoft don’t have a fix for the problem yet but in the mean time they have removed 18362 from the slow ring so machines don’t get stuck in a download/install/fail loop.
Hopefully Microsoft will have a fix soon.
Details from Microsoft:
UPDATE 3/26: Over the last couple of weeks, Insiders in the Slow ring have been receiving new 19H1 builds in addition to also receiving Cumulative Updates. After flighting Build 18362 to the Slow ring on Friday, Insiders began reporting they were unable to complete the update. We have discovered an issue with the Build 18356.16 (KB4494123) Cumulative Update that was preventing the update to Build 18362 from completing successfully. This issue only impacts Insiders who are on Build 18356.16 who try to update to Build 18362. THANK YOU to Insiders who reported feedback on this in Feedback Hub and upvoted – your feedback was immensely valuable in helping investigate this issue over the weekend! The team is currently working on a fix now. In the meantime, Build 18362 will no longer be offered to Insiders who are on Build 18356.16, so Insider PCs don’t continue to try and take Build 18362 and fail. We will post another update once we release the fix and resume the Build 18362 flight. Thank you!