Yellow warning triangle when trying to copy website. Help!

[pwk]

Hi, can anybody help me? I just downloadet the Cryotek Webcopy, but when I paste the URL of the website I want to copy and click "copy", a yellow red warning triangle shows up, but with no text.... I have attached a picture.
What does this mean?
Sorry if it's a noob question, but I have never tried this before.
Thanks in advance and have a nice day.