“unable to verify the first certificate“

For the last week this error has prevented many NPM and CLI tasks from being usable. Frustratingly, it also made them incredibly slow prior to erroring, waiting 15+ minutes (when I had the patience to wait it out) before finally displaying errors.

try completely quitting out of your VPN

I was about to do a full node npm wipe and clean install, when a colleague asked it I was on some dodgy unreliable wifi… I was in my regular office, but following this line of reasoning led me to check my VPN, and eventually to completely quit out of the VPN … and hey presto - everything now works