Resolution

We get this error because of the difference in Angular CLI installed globally Vs local project workspace.

It happens mostly when we are trying to migrate an older Angular framework (Example- Angular 5 or 6 or 7 or 8 apps to Latest (Ex. Angular 9 or 10, or 11).

Steps to fix the issue

Update Angular CLI for a workspace (Local)

npm install --save --only=dev @angular/cli@latest

Make sure to install the global version using the command with ‘-g’

npm install -g @angular/cli@latest

Run Update command to get a list of all dependencies required to be upgraded.

ng update

Next Run update command as below for each individual Angular core package

ng update @angular/cli @angular/core

However (sometimes), we will have to add ‘–force’ and ‘–allow-dirty’ flags command additionally to fix all other pending issues.

ng update @angular/cli @angular/core --allow-dirty --force