Cannot login to WPMU DEV Dashboard


I'm trying to login to WPMU DEV Dashboard to install Pro Sites but it give me a message
Your server had a problem connecting to WPMU DEV. Please try again.

I assked the hosting provider they say " yes this server have been configure php with curl. Kindly revert back to us if you need any assistant."

and I try to install Pro Site Plugin it give me this message "

Fatal error: Call to undefined function switch_to_blog() in /home/nudgatco/public_html/mw/wp-content/plugins/pro-sites/pro-sites.php on line 194

can you help