Microsoft just released Windows 10 Mobile Build 14977 to Insiders in Fast Ring. You can read the full official changelog by clicking here. The build comes with some known issues and one of these issues is quite severe. If you have a device with 8 GB internal storage like Lumia 550 and Lumia 650, you may not be able to install it. Read other known issues below.
Windows 10 Mobile Build 14977 Known Issues:
- Please avoid attempting to install new languages, keyboards, and speech packs on your phone. There is a chance these downloads may get stuck and not finish downloading. If you have existing languages, keyboards, and speech packs installed – they will carry over when you update to new builds. You can use Windows Device Recovery Tool to go back to Windows Phone 8.1 or Windows 10 Mobile, install any languages, keyboards, and speech packs you need and then update to the latest build in the Fast ring as a workaround.
- Windows 10 phones with 8GB of internal storage such as the Lumia 550 and 650 will likely receive an 0x800700b7 error when attempting to update to this build.
- System related notification toasts (e.g. Bluetooth, USB/Autoplay, etc.) do not work.