Rejected-By-UrlScan 404 Errors || IIS and UrlScan – denying request

How Can I Disable URL Scan

1. Go to the <Windows Folder>\system32\inetsrv\urlscan\
2. Check the error first in the log folder
3. Open UrlScan.ini file
4. Set AllowDotInPath=1
5. From Command Prompt (Start -> Run -> Cmd), type “iisreset”, to restart IIS

Xamarin issue with designer in Visual Studio 2015

I have Visual Studio 2015 Update 3, Xamarin 4.2.0.703, Android 7.0 SDK Platform (API 24), Android SDK Tools 25.2.2, Android SDK Build-tools 24.0.3 .

To fix the issue you have to download Android 6.0 SDK Platform (API 23).

Thanks to John Watmuff from stackoverflow.