Over the weekend, we reported that Microsoft's Upgrade Advisor app had stopped working, effectively killing the official upgrade path for Windows Phone 8.1 devices to Windows 10 Mobile. The report came on the heels of news that just 13 handsets would receive the Creators Update, ending support for almost all 8.1 devices, with the exception of the Lumia 640 and 640 XL.

As of today, Upgrade Advisor is once again working, and you can use it to update your device, assuming that it was supported for an official upgrade. And to be clear, it still works for devices that recently lost support with the Creators Update.

When the service stopped working, there was considerable outrage for fans of the platform, since using the Windows Device Recovery Tool to restore a handset brings them back to Windows Phone 8.1, meaning that users have to initiate the upgrade process all over again.

It's unclear, however, how many people this really affected and how many were simply outraged at yet another sign of a lack of support for the platform from Microsoft. According to AdDuplex reports from February, just 17% of Windows phones are on Windows 10 Mobile, with the rest on an older version. This can be attributed to the fact that Microsoft only offered official upgrades for a small subset of devices, and never actually pushed the upgrade to anyone, instead requiring that they find out about it themselves, and then install and run the Upgrade Advisor application.

Even when the app wasn't working, there was still a simple workaround to update a Windows phone. Users could run the Windows Insider app to upgrade their device to 10586.107, turn off Insider builds, and then they would be moved to 14393.1066, which is the latest official cumulative update.

With the small amount of people that are even eligible for Windows 10 Mobile, combined with the fact that they've had over a year to install the update, it would seem that many, if not most of the users experiencing an issue with this are already familiar with the Windows Insider Program.

It's still unclear why Upgrade Advisor stopped working in the first place, as Microsoft hasn't commented on it at all. It could have been something broken on the company's end, or it could have shut it off thinking that no one would notice. Either way, it works now.

Via On MSFT