This version of CLI is only compatible with Angular versions 0.0.0 || ^10.0.0-beta || >=10.0.0 <11.0.0, but Angular version 9.1.3 was found instead.
npm uninstall -g @angular/cli
npm cache clean
npm install -g @angular/[email protected]
npm uninstall -g @angular/cli
npm cache clean
npm install -g @angular/[email protected]