So you have a Lumia phone listed as one of the supported devices by Windows 10 for Phones preview Build 9941.12498. Yet you don’t see a build appearing when you check for the update after properly enrolling to the Windows Insider program.
So, there can be primarily two reason for this issue and there are suggested solutions too.
1) Your phone runs a Windows Phone 8.1 build higher than 8.10.12419.341. We have only one Windows Phone 8.1 build higher than this in the wild: 8.10.14226.359. In this case you need to use the new “Windows Phone recovery Tool” to re-flash your device to a lower build. Follow these steps.
Using the Windows Phone Recovery Tool, begin the process to re-flash your device.
- This will recover the device to a software build that does not have the conflict.
- After the re-flash is complete, DO NOT CONNECT TO WI-FI. This step is critical to prevent the device from automatically taking a background update to the OS version that contains the conflict.
- Once you reach the Start screen, go to Settings > Phone update and uncheck the box for “Automatically download updates if my data settings allow it”.
- Perform a power cycle on the device, turning the device off and then back on.
- Turn Wi-Fi on and download the Windows Insider application to the device
- Launch the Windows Insider application and select the desired Insider state (Slow or Fast).
- Go to Settings > Phone update and tap Check for updates.
Accept the update and follow the on-screen directions to complete the process for updating to the Technical Preview.
2) If your devices has the build lower than 8.10.14226.359, check whether you have enrolled to Insider Fast or Insider Slow. You need to re-enroll yourself to Insider Fast, if you have chosen Insider Slow in the first place, as those enrolled with Insider Fast get the builds first and face more bugs too.