Cannot log in via WPMUDEV Plugin


Suddenly seeing a lock symbol on the dashboard menu option on the left within my WPADMIN.
When I click, I see a login as per screenshot. But when I enter my valid credentials I dont see my dashboard, but rather the following message:

Your server had a problem connecting to WPMU DEV: "HTTP Error: 403 "Forbidden"". 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 with a GET HTTP request via fsockopen or CURL?"

Could someone explain what I have done?