Question: I starting getting this error on my Angular app:

> 
> The Angular Compiler requires TypeScript >=2.7.2 and <2.8.0 but 2.8.3
>  was found instead
> 
> 
> 

and when I try to downgrade typescript to the right version doing:

`npm install -g typescript@2.7.2` it says updated 1 package.

when I verify typescript version using 
`npm view typescript version`
I still get 2.8.3

I even tried removing typescript entirely using `npm uninstall -g typescript`

but when I verify typescript version again
`npm view typescript version` I still get 2.8.3

What are the commands to properly purge and restore typescript to a previous version such as 2.7.2?

I'm running node v10.0.0 and npm v6.0.1

When I run `npm list -g typescript` I see the correct version coming 2.7.2 but still version 2.8.3 is installed somehow globally

Answer: 
Installing "@angular/compiler-cli": "7.0.0-beta.4" resolved this issue.
I use "typescript": "3.0.3".
Had the same issue (amongst many others) after updating to macOS Mojave.
Fixed it by removing node\_modules and package\_lock.json manually, changed in package.json from "typescript": "~2.7.2" to "typescript": "~2.8.0" and ran npm install.