Question: I am running an Angular Application I am getting these popup in vs code whenever I am opening it. However, the ng serve command is working fine and it's serving(running) the app successfully.

But I am getting this error in console.
[![console error](https://i.stack.imgur.com/mX73o.png)](https://i.stack.imgur.com/mX73o.png)
[![this popup coming in vs code](https://i.stack.imgur.com/uJkvM.png)](https://i.stack.imgur.com/uJkvM.png)
[![ng serve is serving the app](https://i.stack.imgur.com/I1exq.png)](https://i.stack.imgur.com/I1exq.png)

Answer: 
Angular Language Service Extension has one bug which is reported to their git repository.

My solution will work for Angular Projects which is running < Version 9.0

To resolve this issue you have two ways.
Solution 1: Downgrade extension version

1. Downgrade [https://marketplace.visualstudio.com/items?itemName=Angular.ng-template](https://i.stack.imgur.com/wyMlG.png) to 11.2.14
2. Remove Node Module
3. Run npm install
4. Run npm start or ng serve

Solution 2: (For Version 12)

1. Open Vs Code
2. Go To Files ==> Preference ==> Setting
3. Under Extension Select Use Legacy View Engine Checkbox.
4. Run npm start (If you're facing any issue then kindly close VS Code and Remove
node\_modules folder and Run npm install

[![enter image description here](https://i.stack.imgur.com/wyMlG.png)](https://i.stack.imgur.com/wyMlG.png)
reinstall vscode extension Angular Language Service@v11.2.14 resolve my problem.