Windows 10 Mobile Insider Preview Build 10549 and Build 10572 both required testers to revert back to Windows Phone 8.1 before updating to the latest builds of Windows 10 Mobile. This was by no means a deal killer for testers, but it was an annoyance nonetheless.
Today, Microsoft has finally killed off the upgrade bug that affected those two most recent released with Windows 10 Mobile Insider Preview Build 10581. You can now directly upgrade to newer builds from here on out without backtracking to Windows Phone 8.1.
With regards to the rest of Build 10581, we have some good news and bad news. The good news is that a wealth of additional bugs have been fixed, including issues with dual-SIMs, Visual Voicemail, Chinese QWERTY keyboard support, and “Hey Cortana” functionality on Lumia 930, Lumia 1520 and Lumia Icon smartphones. In addition, there have been enhancements made to battery life, photo sharing, text prediction and autocorrect.
The bad news is that there aren’t any new features to speak of in this build. But even that downside could likely be seen as a positive. Perhaps holding the line new features means that the development phase of Windows 10 Mobile is winding down — Microsoft originally hoped to release Windows 10 Mobile in late summer/early fall.
“We’re very happy to have the upgrade bug behind us which caused a few unusual flights, and are hugely appreciative of the Windows Insiders who did the extra work to re-flash and try those builds,” said Microsoft’s Gabe Aul. “For those of you who chose to wait it out, we hope you’ll find this build worth the wait.”
We’d prefer that Microsoft take its time to make sure that it puts out a fully polished operating system, but part of us hopes that we’ll see a final, public release of Windows 10 Mobile before the close of 2015.