Sounds just like my lazy cousin

There are many reasons why you might not be able to cast to your Chromecast, both from your computer and from your mobile device.

Some of the most common reasons for this are:

Any of these issues will disrupt your ability to cast to your Chromecast. This means that when you use a service like YouTube or Netflix, the Chromecast icon will not appear or will not work when you click on it.