On latest preview of Windows 10, there a no menus showing up. Either from main menu bar or context menus in graphs.
I’m using latest version from github master branch, but also tested on several binary versions from launcher.
This problem is most likely not related directly to Unreal, as several other people also have the same issues, with latest windows 10 preview.
What seems to be an issues is that menu is not rendered. In blueprint graph, you can still select items from menu (even though is not visible), by typing name and pressing enter.
Posting it here mainly to give you guys a hint, that something doesn’t work, and so you can route it to Microsoft more efficiently than we can