If you've upgraded to Visual Studio 2015 RTM with the associated Universal Windows Platform tools, you may have realised that you can't deploy apps to a real Windows Phone that's running the current Windows Insider Preview build for Windows Phone. This is because the version of the SDK, which has a version/minversion of 10.0.10240.0, is higher than what's currently available for the phone. For application development and testing this means using the emulators that ship with the SDK.
Of course, this isn't a great story as lots of developers much prefer debugging on a real device. In fact there are scenarios where a real device is the only way to test some scenarios. I came across the following post that provides a temporary, NON-SUPPORTED solution.
The solution rests on manually changing the TargetPlatformMinVersion property in the UWP project file to be the same as what's running on the phone (in my case 10.0.10166.0). Don't change the TargetPlatformVersion property - doing this will mean that you won't be able to open the project in Visual Studio since that version isn't supported with the SDK.
WARNING: Whilst making this change may mean that you can debug your application on a real device, just be aware that it may through weird errors if you happen to try to access an API that has actually changed between 166 and 240 builds. Your code is still going to be built against the 10.0.10240.0 API set, you're just lying in the package manifest, claiming that your app will run on a previous version.
As you can imagine this has been designed with future versions in mind. If you open the project properties dialog for the UWP application you'll see that on the Application tab there is a Targeting section. In the current SDK there is only one option for the target version and min version. Going forward you can imagine that a future SDK will allow for selection of 10.0.10240.0 (the current version) and a future version (where APIs may have evolved).