Can not login to Dashboard and connect

Hello,

i installed the plugin but can not login. Become following error Message:

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/wdp-un.php with a GET HTTP request via fsockopen or CURL?"

Cheers Andy