Node.js Port 3000 already in use but it actually isn't?

Question

I have been working with a node.js project for a few weeks and it has been working great. Usually, I use npm start to run my app and view it in a browser on loc

Answer 1

I have solved this problem because the MongoDB or there is another app u had run it before on this port, so to solve it kill the process from task manager, or just change the number of the port from 3000 to any other one.