Q: 403 Forbidden Error while installing Kendo Angular Buttons I am getting following error while installing angular kendo buttons:
npm ERR! code E403
npm ERR! 403 Forbidden: @progress/kendo-angular-buttons@^3.0.3
I am using following command :
npm install -S @progress/kendo-angular-buttons

And I have provided kendo credentials using 
npm login --registry=https://registry.npm.telerik.com/

I have registered for trial version of Kendo UI For Angular
How to overcome this issue or am i missing out something. 

A: 
Starting from this week the Kendo UI for Angular packages will be
  published on npmjs.com to address the many concerns users were having
  with this distribution channel.
Please remove the following lines from your .npmrc file to switch to
  the default registry:
@progress:registry=https://registry.npm.telerik.com/
  //registry.npm.telerik.com/:_authToken= The npm registry at
  https://registry.npm.telerik.com will continue to function until all
  users have migrated away from it.
IMPORTANT: New versions of the packages will be published only on
  npmjs.org.

from github
So you can download this package without the authentication npm i -s @progress/kendo-angular-buttons like this, you just need to remove the telerik npm registry.

A: This solved my problem:
npm install -g npm@3.10.10

Thanks to jeffmodzel answer on github.
https://github.com/npm/npm/issues/18567
