How do you tackle - Unable to run app on emulator error?

This is the error message i keep getting when i try to run app on emulator

RuntimeError: abort(Error: could not connect to TCP port 5554: cannot connect to []( No connection could be made because the target machine actively refused it. (10061)). Build with -s ASSERTIONS=1 for more info.

What are the best ways to tackle this?

Please provide more information.

What app?

What emulator?

Where is it running and how are you connecting to it?

It might be a firewall blocking it or the service isn’t actually running on that IP:PORT

Android app and on an android emulator.

What emulator is it?

The error is usually just that nothing on the system is accepting a connection on the specified port. But as said, it might be getting blocked as well.