iframe youtube.com refused to connect

Code Example 1

First, take a close look at your code:

<iframe width="420" height="315" src="https://www.youtube.com/watch?v=eI4an8aSsgw">
</iframe>

If you change the URL in the src attribute to the scheme above, your embed should work like you expect:

<iframe width="420" height="315" src="https://www.youtube.com/embed/eI4an8aSsgw">
</iframe>