When I try to install the Windows Phone Template Pack on Visual Studio Community 2015, the following error is obtained.
What is the reason? Where can I check the error log from?
Couple of issues:
The Windows SDK link you provided (http://www.microsoft.com/en-in/download/details.aspx?id=8442) is for Windows 7. It is not compatible with Visual Studio 2015 for Windows Phone development.
I think this error you're seeing with the Windows Phone Template Pack (HRESULT: 0x80070057) is because the Windows and Windows Phone 8.1 Tools are not installed on your computer along with Visual Studio Community 2015.
I am able to reproduce this only when the Windows and Windows Phone 8.1 Tools are not installed.
If I click skip, then I see the error dialog you included above.
To resolve this issue,
If you're running Windows 8.0/8.1/10 x64 Professional or higher with a Hyper-V capable computer and then you should also be able to install the Windows Phone 8.1 emulators.
-Paul Chapman [MSFT]