Solution:
npm cache clean --force
rm -rf node_modules package-lock.json
npm install
Try using legacy peer dependencies:
npm install --legacy-peer-deps
Solution: Ensure dependencies are installed:
npm install
Try rebuilding:
ng build --force
Solution: If using Node.js backend, allow CORS:
const cors = require('cors');
app.use(cors());
For Apache, update .htaccess:
Header set Access-Control-Allow-Origin "*"
Solution: Kill the process running on port 4200:
npx kill-port 4200
Or start Angular on a different port:
ng serve --port=4300
Solution: Ensure the correct base href is set:
<base href="/">
If using Apache, update `.htaccess`:
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.html [L]
</IfModule>