Microsoft has just pushed Windows 10 Mobile Build 14356 to Windows Insiders in Fast Ring and you can read the full official changelog including fixes by clicking here. The Build however brings its own set of known issues and you may like to read them. In case you are facing other upgrade issues or errors while installing it you can refer to our guide.

  • We are continuing to investigate battery life issues impacting certain devices. We have fixed a few bugs that improve battery life but we have more work to do here.
  • We are investigating data issues with some Dual-SIM devices where cellular data doesn’t work correctly with a second SIM. Several issues relating to cellular data with Dual-SIM devices have been reported by Insiders with the last two Mobile builds and we’re investigating these reports.
  • In some cases, the new Cortana features highlighted above may not work. Restarting your phone should fix the issue and get the features working