Lately I created a ASP.NET MVC Core project from scratch using Visual Studio 2017 (15.6.3). I discovered the usual JavaScript frameworks:
The following blog worked for me, although it claims the issue would be fixed in 15.8 which is the opposite of this issue:
https://blogs.msdn.microsoft.com/webdev/2018/07/05/workaround-for-bower-version-deprecation/
I have updated the .bowerrc file to include:
"registry": "https://registry.bower.io"
I then right clicked the bower.json and Restore packages. Then voila!