I recently had this error in Unity. Unity Curl error 7: Failed to connect to cdp.cloud.unity3d.com port 443: Connection refused
For a few days, I had been working on this little Unity Project when this error message started to appear. From one day to the next. No changes had been done. Everything worked when I pushed it to my Gitlab the night before.
Then I remember a change I did to the router after I closed Unity the night before. I changed the DNS. Everything else seemed to work. So I tried to ping cdp.cloud.unity3d.com. No route to host. Ok.
Anyway, I changed the DNS back to 184.108.40.206, and the error messages in Unity error disappeared. Nice!
So if you get the same Unity curl error 7, check your DNS if you have your own. Or Proxy settings if you are behind a Proxy. Anything that prevents you from connecting to cdp.cloud.unity3d.com.
Miss the intros on 8 and 16-bit computers from the 80-90s? Check out how to make an easy intro.
Unity just published 3-month free access to Unity Learning Premium due to the circumstances in the world. Check it out.