From the new Insider Hub app installed with build 9879

Known Problems in build 9879

As with the last preview build, you’re getting code hot-off-the-presses which means there are a few problems. For the first two, we’ll be publishing fixes to WU updates shortly, but the remainder will not be fixed for 9879.

•In some cases you may get a black screen when trying to log-in or unlock. The only option is to hold the power button to hard reboot.
•You will be unable to connect to Distributed File System network locations.
•Some systems may see disk growth of 20GB+ due to driver install duplication. On systems with low disk space this can block setup and cause a rollback to the previous build.
•Skype calls will disconnect and Music will stop playing if apps are minimized.
•There are several known issues with screen sharing with Lync.

Changes in 9879 based on Feedback:
Here are just some of the changes we’ve made based on direct feedback from Insiders.
•One of your top suggestions really made an impact on our designs for the taskbar. With 9879, you can now hide the Search or Task view buttons on the taskbar—right-click on the taskbar and uncheck the check boxes for whichever button you want to hide.
•We heard that the new minimize and restore animations for apps we introduced in the last build were a bit jarring, so we’ve updated them. Check out the new animations and let us know what you think.
•We also heard that it was too hard to find the charms and full screen button in modern apps. We have replaced the three dots in the Window chrome for modern apps with a “hamburger-style” icon (three lines) that should make it easier to discover.
•Less visible but still super important are all of the crash and hang problems that you’ve reported as you’ve been using the builds. We’ve fixed a lot of the problems that you’ve hit. You're directly contributing to our ability to make Windows 10 more stable for everyone. (These also work kind of like “votes” so think of it this way: as you use the product and send in your votes it will work better for you than for your friends who aren’t in WIP!)

We’re still working on many other things that have been influenced by your feedback, but we really wanted to start by showing how you’ve directly made an impact on this release. More to come.