This error means that there is a problem with the TLS certificate. Typical suspects are, in rough order descending likeliness, according to my experiences working as a youtube-dl developer:
- Censorship by your country, especially if you are located in or near China, Pakistan, or other non-democratic countries. You can use a VPN or TOR with a bridge to avoid the censorship.
- Censorship by your company, school, or ISP. Again, a VPN (or proxy) can avoid this.
- Local anti-malware software trying to intercept connections.
- Local malware software trying to intercept connections.
- A proxy server that is now misbehaving. Add
-v
to the command line to see whether one is configured.
- A local configuration problem, i.e. missing certificate store or so. This depends a lot on how you installed youtube-dl.
- A configuration problem on YouTube's side.
In any case, you can avoid certificate checking by passing in --no-check-certificate
. However, note that this will allow nation states, ISPs, schools/companies, hackers, and other (semi-)malicious parties to log, intercept, and change your video traffic.
Note: The video https://youtu.be/0Ef9GudbxXY is not available in format 137. Simply leave out -f
to get the best available format.