Fix FatalDiagnosticError

✅ Solution

FatalDiagnosticError in Angular usually indicates a problem with your project's dependencies or Angular Language Service configuration. Try clearing your `node_modules` folder, running `npm install` or `yarn install` to reinstall dependencies, and restarting your IDE or language service. If the problem persists, check your `tsconfig.json` file for any misconfigurations or incompatible compiler options.