Can't connect to Dashboard plugin

I tried to log into the wpmudev dashboard from one of my sites and got this error:

Your server had a problem connecting to WPMU DEV: "Error unserializing remote response.". 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?"

I have UFW firewall set up on the droplet but not sure if that is causing the error. What should I do??