I can't download anything, the Paste link button is grayed out. We get this support request quite often from our users. There are several reasons why it may be grayed out. The most common is that you didn't copy the link, but an image or file.
The image below shows you how to copy a link from a YouTube video in two easy steps. You need to click the Share button first and then click the Copy button to copy the link to the system clipboard.
Now you can paste the link and download it. Hope this helps.