Last night, Microsoft released a new Windows 10 Insider Preview build to the Fast ring. But it also moved the previous Fast ring build to the Slow ring, indicating that it is on the verge of completing the Fall Creators Update, or Windows 10 version 1709.

“Today we are releasing Windows 10 Insider Preview Build 16299 for PC to Windows Insiders in the Fast ring,” Microsoft’s Dona Sarkar revealed last night. (In a bit of inconvenient timing, I was in a cab at the time heading to our Orlando meet-up.) “As we mentioned previously, we are now at the point of the development cycle for the Windows 10 Fall Creators Update where our focus is now on stabilization for release to the world.”

This new build comes with no known issues list, which I continue to find disappointing. But it does include the following fixes:

• A fix for an issue some Insiders were experiencing where after upgrading to recent flights their optical drive wouldn’t be listed under This PC.
• A fix for an issue where Microsoft Edge might crash when scrolling embedded PDFs.
• A fix for an issue resulting in some Insiders seeing 0x80070005 when trying to upgrade to the last few flights.
• A fix for an issue where using the Automatic File Download notification to block an app from downloading files wasn’t working for UWP apps.
• A fix for an issue resulting in Windows Defender potentially downloading files selected to be online-only after using the file picker dialog and viewing their thumbnails.

Separately, Ms. Sarkar also noted that build 16294, which was released to the Fast ring just 5 days ago, has moved quickly into the Slow ring as well.