Why is the file node_modules/rxjs/operator/delay.js not being built?

Question

Angular

Actually I can not understand why this file is missing? The corresponding error is thrown in the browser console:

Failed to load resource: the server responded with a status of 404 (Not Found) 
http://localhost:3000/node_modules/rxjs/operator/delay.js

Well, in the console with npm start, this file is also 404

Help me figure it out, please

Answer 1

Updated ANGULAR, everything worked. Hm...