According to Microsoft, a "subset" of users are having issues installing the most recent Cumulative Update for Windows 10. The company still hasn't posted a fix, but we have one that appears to work.
Build 14393.187 RSS
Microsoft today released a new cumulative update for Windows 10 Mobile users in the Slow and Release Preview rings, bringing the build number to 14393.187. The update contains fixes and improvements.
Microsoft today released another cumulative update for Windows 10 users, including those using the Anniversary Update, version 1511, and even the original build of Windows 10, now known as 1507.