Strange subfolder "DTAR_08E86330_4835_4B5C_9E5A_61F37AE1A077_DTAR" created in VS2015's UWP solution folder

Question

There's actually an issue filed on Connect, which is currently reviewed by Microsoft. So brings in some room for the reasonable suspicion that this is a bug of Visual Studio 2015.

There is also a workaround available:

Posted by DaisyDave on 12/15/2015 at 2:40 AM
Opening solutions from within the IDE stops these folders appearing.

It seems to be (finally) fixed in recent Visual Studio Update 3 RC (works for me at least).

Also there is another "more permanent" workaround from EricStj - MSFT (copy-pasted from his comment to relevant issue here) for those who would prefer to wait for RTM version of this update and have to skip current RC version:

The fix didn't make it into Update 2. It should come out in Update 3. To workaround you can copy this file replace this file "C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETCore\v5.0\GlobalDTARSettings.proj" with the version from here: https://gist.github.com/ericstj/b40dd3846c3faec5ea1ba55fce64d1f8.

In general I open solutions from Windows Explorer rather than from within Visual Studio. If you're like me the Connect issue mentioned in Andreas' answer has a second workaround, for opening the solution from Windows Explorer:

Posted by Dee Key on 3/4/2016 at 11:22 AM
From the Windows File Explorer right-click on the solution file and Open with Visual Studio 2015.