Loads of new build have come out the last few weeks (16291, 16294, 16296 since last post), leading up to the Fall Creators update, mostly bug fixes are added, here’s what’s new in 16299, released yesterday:

Happy Upgrading!

General changes, improvements, and fixes for PC

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

Source: Windows Blogs