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

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

Answer 1

I did next steps:

• removed package-lock.json;
• npm install -g --save typescript@2.7.2;
• npm uninstall -g --save typescript@2.9.2;
• in package.json, section "devDependencies" updated string with typescript as "typescript": "~2.7.2".

After all above run in project's terminal ng serve --open (I've been using IDEA 2018.1).

Answer 2

This is just because in your projects package.json file has

eg."devDependencies": {"typescript": "~2.8.3" }

and in your machine where angular cli installed has "typescript": "2.7.2" version.

You can check this by ng -v or ng v.

So, just open package.json update your typescript version and run npm install and you are done.

Answer 3

Installing "@angular/compiler-cli": "7.0.0-beta.4" resolved this issue. I use "typescript": "3.0.3".

Answer 4

Downgrading to typescript 2.9.2 (npm install typescript@2.9.2) and re-running ng update --all still yields the error (twice):

Package "@angular/compiler-cli" has an incompatible peer dependency to "typescript" (requires ">=2.7.2 <2.10", would install "3.1.3"
Verified that version 2.9.2 of typescript was in node_modules.

Answer 5

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.

Answer 6

I did the following:

• Delete manually the folder node_modules
• Delete manually the file package-lock.json

• In the file package.json be sure to set the dependence of TypeScript as

   "typescript": "2.7.2"
  

• run npm cache clean -f

• run npm install

That work for me.