Error: Schema validation failed with the following errors: Data path “” should NOT have additional properties(project)

Question

After migrating application from angular 5 to 6, on running ng serve the following errors pop up.

Schema validation failed with the following errors:

Answer 1

The issue is generally because of a version mismatch in your package.json file.

In my Angular 7 app, I have changed "@angular-devkit/build-angular": "^0.800.2" to "@angular-devkit/build-angular": "~0.7.0".

Then I ran the command npm install after deleting node_modules.

Aside: Use ^ carefully. Your working code may not work in the future if there is a major change in the package used.