Polymer 1.0 Vulcanize Error

I recently started getting following error when running "gulp" on polymer starter kit:

Starting 'vulcanize'...
ERROR finding /starter-kit/app/elements/bower_components/bower_components/promise-polyfill/Promise.js
ERROR finding /starter-kit/app/elements/bower_components/whenever.js/whenever.js
ERROR finding /starter-kit/app/elements/bower_components/bower_components/bower_components/bower_components/bower_components/web-animations-js/web-animations-next-lite.min.js
ERROR finding starter-kit/app/elements/bower_components/paper-datatable/weakCache.js
ERROR finding starter-kit/app/elements/weakCache.js
:starter-kit$

I spent multiple hours looking on google but couldn't find a concrete answer. The same code and command works on my collegues machines.

I figured out that one difference between their and my machine was the npm repository. They were using external repo while I was using internal repo.

The Polymer/vulcanize team released 1.14.9 and it had a critical bug (https://github.com/Polymer/vulcanize/issues/332). As soon as they found that, they unpublished 1.14.9 version. However, before they could unpublish, our internal repo had cached it.

To resolve this I had to manually downgrade to 1.14.8 which I did by changing repo path to public npm repo.