I can't log into WPMU on my site

I’m getting this error when I try to login. I tried logging out and back in, because I couldn’t update the upfront themes….

Your server had a problem connecting to WPMU DEV: “Couldn’t resolve host ‘premium.wpmudev.org'”. Please try again.

If this problem continues, please contact your host with this error message and ask:

“Is php on my server properly configured to be able to contact https://premium.wpmudev.org/api/dashboard/v1/ with a POST HTTP request via fsockopen or CURL?”