I installed yesterday
- Windows 10 Fall Creators Update SDK (version 10.0.16299.15),
 - Microsoft Mobile Emulator for Windows 10 (version 15254.1)
 
After installing the new SDK, my emulators completely disappeared from the start button. Even the local machine. I have Visual Studio 2017 (version 15.4.1). Secondly, when I run the Visual Studio installer, I see the necessary things for the SDK and the emulators are checked.
The SDK and Mobile Emulator options confuse me. Also, I was tired of repairing Visual Studio, but no luck.
Edit: all that is indicated in the "Start" button is "Start" and "Download new emulators" (not even a local machine).
Thank you for your help.
UPDATE

4 . 1 UWP, 2 1 . / ( ).
, SDK
SDKs
- Windows 10.0.16299.15
 - Windows 10.0.15063.468
 - Windows 10.0.15063.137
 - Windows 10.0.14393.795
 - Windows 10.0.14393.33
 - Windows 10.0.10586.212
 
- HoloLens Emulator 10.0.14393.0
 - HoloLens Emulator Image 10.0.14393.0
 - 10.0.15254.1
 - 10.0.15063.137
 - 10.0.14393.0
 - 10.0.15254.0
 - 10.0.15063.0
 - 10.0.14393.0
 
.