Angular CLI karma tests not running

I have an Angular2 project, created with Angular Cli 1.0.0.rc2

When I run ng test, the project builds (without errors!), karma launches chrome and displays

"Karma v1.4.1 - connected" and

"Chrome 56.0.2924 (Mac OS X 10.12.3) is idle"

Soon after, I get an error in the console saying You need to include some adapter that implements __karma__.start method!

Funny part is that the test.ts that is called to start the test is actually running (confirmed with console.log('test')) and it does have a __karma__.start() call.

Anyone can help?

I'm using Node 6.10.0 and NPM 3.10.10.

via Jan Schuermann