Windows.Data and Windows.UI references could not be found

[alievkomiljon]

I cloned and opened the project. On the references list there were Window.Data and Window.UI, which had yellow warning sign. I deleted and tried to add them again but could not find them on NuGet Package Manager.

[haveachin]

Just saw your issue. Sorry for the very late reply, but I also had this issue. It is related to Windows 10 push notifications. I'm not sure how I fixed it, but it works for me when I pull it on a freshly installed Windows 10 system.