what is this "scheme don't have a registered handler" error?

I am working on a node app.
i have an ejs file , where on clicking a button a get request is made to this url `localhost:3000/posts/business-economics`
but the page doesn't load up and this error is shown in the console

> Failed to launch 'localhost:3000/posts/business-economics' because the scheme does not have a registered handler.

I encountered the same error while working with the localhost. I was trying to redirect to localhost:3000 and I got this error flashing on my console.
It turns out that it's because the **http:// is missing** from the url you're trying to load. I'm amazed to see that no one has answered this yet.

Sometimes, juste to to restart your app could change something or to check again the url path that you give it coud also be a mistake over there

you must set address protocol before url ,like:


returnUrl = window.location.protocol + "//" + window.location.host + Path

Another reason which I also faced. If href tag has wrong spelling of javascript.

<a href="javascript:;" onclick="myfunction()">Action</a>

At the end of the day, an URL with the wrong format may end on such error.

A window.open command with the wrong format on the first parameter may throw this error too:
``` lang-js
var emptyWindow = window.open('Window title', '_blank');
// Console output:
// Failed to launch 'Window%20title'
// because the scheme does not have a registered handler.'
```
In the case above, the developer (me, some time ago) forgot that the first parameter must be there even when you want to open a blank page:

`var emptyWindow = window.open('', 'Window title', '_blank');`

The value is optional but not the parameter itself.

A malformated first parameter may throw this same error too.