It has to be pointed out that this is just a warning and the Node.js process will still execute the however many event listeners you have. It won't terminate the process, it will only appear once per event and it is more about pointing out problems in your source code. According to the Node.js Documentation, there is a maximum of 10 listeners per a single event, more than 10 will cause a
process.on("warning") call resulting in this warning. More info on this here.
Occasionally you might run into the below warning in your developer tools.
This chromium warning presents itself when there is a potential Memory leak. This warning itself comes from the Node.js source code. More info here. This warning helps you to prevent memory leaks. Node.js processes can run for a long time; when you have a bug in your code and create a new event listener before cleaning up, or you don't use existing ones, the memory usage of this process will slowly grow and can affect your application's servers at some point.
Our suggestion would be to go into your code and looking at potential instances where an event listener is referred to more than once.