A couple of weeks ago, Microsoft released Windows 10 Insider Preview build 14931 to the Fast ring, bringing various fixes, improvements and known issues. Today, it announced that the same build has now been released to the Slow ring, making it the first Redstone 2 (RS2) preview to make its way beyond the Fast ring.
The very first Insider Preview to be released from the RS2 Development Branch was build 14901, which headed to Fast ring PCs in mid-August. Microsoft said that early RS2 releases would focus on structural improvements rather than new features, and warned that they would likely be quite unstable, with plenty of "bugs and other issues".
Microsoft's decision to push build 14931 to the Slow ring is therefore an important milestone, as it signals a new level of stability in its RS2 builds. However, even Slow ring builds aren't perfect, so if you're not prepared to deal with potentially troublesome bugs and problems on your device, you should still consider downgrading to the Release Preview ring, or opting out of the Insider Program entirely, at least until later in the RS2 development process.
Along with its Slow ring release of 14931 today, Microsoft also revealed that it's fixed two issues in that build, which are being delivered as the KB3195841 hotfix through Windows Update:
FIXED: While using Narrator and Groove Music, if you navigate to the progress bar while a song is playing then Narrator will continually speak the progress of the song e.g. update with the current time of the progress bar every second. The result is you will be unable to listen to the song or hear any other control you navigate to.
FIXED: For keyboard users, using tab to navigate the Settings app will not work in this build. The arrow keys should work as a temporary workaround.
Source: Windows Blog