Yesterday Microsoft updated the release notes for Windows 10 Insider build 17063 to add to the list of known bugs related to this version. It so happens that one of these bugs is one that I am having after upgrading to this build.
According to the updated release notes these bugs are related to the Windows Out-of-box-experience, activation issues, and having problems hearing audio in apps like Firefox.
ADDED 12/21: While navigating through OOBE, some of the buttons in the pages may not display correctly. In case of running into this, use the keyboard and tab forward through the page’s controls, or hover over blank areas of the screen and buttons will be rendered in the process. This should unblock you and allow you to continue through the OOBE flow. ADDED 12/21: We are investigating reports that Windows shows that it “needs activation” and trying to activate fails after upgrading to Build 17063. ADDED 12/21: Audio may not work in certain apps like Firefox after upgrading to Build 17063.
Unfortunately, at this time there is no fix for these issues and you will have to wait till the next release to resolve them.
Another issue that is being discussed a lot on the Microsoft Answers site is Insiders being unable to install this build. Some have suggested that you can disable virtualization or USB ports in the motherboard settings to resolve this issue.