cannot smush images - cURL error 6

I am unable to login after installing the WPMU DEV.
I can't smush images. Keeps on getting this error:

our server had a problem connecting to WPMU DEV: "cURL error 6: Couldn't resolve host 'premium.wpmudev.org <http://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/ <https://premium.wpmudev.org/api/dashboard/v1/>; with a POST HTTP request via fsockopen or CURL?"