This falls under the #protip category of things…

If you’re using the Docker Beta for Windows (the Hyper-V one) and you find that you can’t do any docker pull - try disabling Malicious Website Protection in your Anti-virus/Anti-Malware suite. Yep - turns out these things which filter traffic might actually cause a problem for you!

People kept thinking it is to do with IPv6 on the forums - it’s not.

It’s now just annoying that I have to keep turning it on after doing dev. work.