karma:unit fails with tmp browserify errors

I'm having the following issue and I'm the only developer in a team of 6 experiencing this issue.

When I run the following command: $ grunt unit (Task: clean:reports install_custom_coverage karma:unit), I receive the following result:

...
DEBUG [web-server]: serving: C:\Dev\life-web_components\node_modules\karma\static/context.html
PhantomJS 1.9.8 (Windows 7) ERROR
  TEST RUN WAS CANCELLED because this file contains some errors:
    C:/cygwin/tmp/2cfb2e9479b44a59f6d3c57d366bd5b4.browserify


IE 8.0.0 (Windows 7) ERROR
  TEST RUN WAS CANCELLED because this file contains some errors:
    C:/cygwin/tmp/2cfb2e9479b44a59f6d3c57d366bd5b4.browserify

Chrome 41.0.2272 (Windows 7) ERROR
  TEST RUN WAS CANCELLED because this file contains some errors:
    C:/cygwin/tmp/2cfb2e9479b44a59f6d3c57d366bd5b4.browserify



DEBUG [karma]: Run complete, exiting.
DEBUG [launcher]: Disconnecting all browsers
DEBUG [framework.browserify]: cleaning up
DEBUG [launcher]: Process PhantomJS exited with code 0
DEBUG [temp-dir]: Cleaning temp dir C:\cygwin\tmp\karma-34162292
DEBUG [launcher]: Process Chrome exited with code 0
DEBUG [temp-dir]: Cleaning temp dir C:\cygwin\tmp\karma-61774528
DEBUG [reporter.junit]: JUnit results written to "C:/Dev/life-web_components/reports/unit_tests.xml".

DEBUG [launcher]: Killed extra IE process 6528
DEBUG [launcher]: Process IE exited with code 0
DEBUG [temp-dir]: Cleaning temp dir C:\cygwin\tmp\karma-94332604
Warning: Task "karma:unit" failed. Use --force to continue.

Aborted due to warnings.

I've tried a range of suggestions, restarting CMDER, restarting machine, deleting node_modules, reinstalling global node modules, set autoWatch to false and various other attempts with no luck.

As I'm the only developer in the team experiencing the issue, it appears to be environment related.