Microsoft released Windows 10 Insider build 15019 to Fast ring Insiders yesterday. Unfortunately, there's 2 issues that are affecting installation of the latest build. Jason on the Windows Insider team has provided a workaround for each issue.
Error 0xC1900401 or "build not yet available"
The first issue is encountered via Windows Update. Upon attempting to install the build, it will claim it is "not yet available" for that device, or provide an error code of 0xC1900401. This issue affects devices running the x86 version of Windows 10.
For this particular issue, it is server-side. Microsoft is working on resolving the situation and advises that Insiders keep checking for an update. It will eventually begin to install as they roll it out correctly into your region.
PC scans and Finds 15019 but appears to hang on "Initializing..."
As reported by Callum Moffat on Twitter, there's a somewhat minor issue with the Windows Update screen:
— Callum Moffat (@callum90ish) January 27, 2017
It will claim that it is attempting to initialize the update... but doesn't seem to progress. It can affect all Insiders, but seemingly some are not experiencing this issue.
There's 2 workarounds for this one. Usually, if you leave it on initializing, it will eventually correctly download and update as usual. Alternatively, if you don't wish to wait, there's a more direct route that you can take:
- Click the Start button
- Type services and launch the Services panel
- Scroll to Windows Update
- Right-click and select Stop
- Restart your PC
- Re-check for updates
- The update should proceed as expected
Let us know how you get on with build 15019 in the comments below!