Known Issues - Windows 10 Mobile Insider Preview Build 14267
Visual Voicemail notification and delivery is not working in this build; causing devices to not receive any new visual voicemails. You can manually check your voicemail by calling your voicemail to listen to any new messages. You can call your voicemail within the Phone app by clicking “…” > Settings > “Change more settings for Phone” > “Call voicemail”; this will also leave the Voicemail call in your history to make checking voicemail easier.
ADDED 2/20 – Several Windows Insiders with a Lumia 550 have reported an issue where their phone no longer charges or connects via USB after upgrading to Build 14267. If you have a Lumia 550, we recommend holding off going to this build. If you have hit this issue we recommend rolling back to Build 10586 using the Windows Device Recovery Tool. You will need to connect your phone to your PC via USB first, open the Windows Device Recovery Tool and choose “My device was not detected”, choose “Lumia” and turn off your phone and let it reboot in order for the Windows Device Recovery Tool to detect your phone and reinstall. If you need to download the image, your phone may reboot back into the OS, once the image finishing downloading completely – reboot your phone again and it should begin reinstalling Windows 10 Mobile. If your Lumia 550 is really low on battery, switch your phone into flashing mode by turning your phone off first and press power button and then volume up until you see a lightning bolt on your phone’s screen. This will allow your Lumia 550 to charge. You should let it charge a bit before using the Windows Device Recovery Tool to roll back to Build 10586.