Just so we’re on the same page – you you have yarn configured as the package manager in angular-config.json, but attempting to start it using the Servers view fails? Does the applications start if you manually start it with yarn start?
I’m sorry I missed your screenshots. Yes, some of our code is internally wired to use npm. If you use Yarn to add the angular-ide package to your project manually, then the server start should directly move on to running ng serve, and you should hopefully not have this problem.
I’ve filed a bug for better out-of-the-box support for Yarn when a user chooses this instead of NPM. Apologies for the inconvenience caused.