Schema validation failed with the following errors:
Data path \".builders[\'app-shell\']\" should have required property \'class\'.
Schema validation failed with the
What i did was to uninstall and install the "^0.13.0".
I confirm/ support this last answer. It worked for me as well.
I had uninstall version "^0.800.0" and installed the "^0.13.0".
rebuild your project it will work fine.