Can't conntect to Mailchimp api

I have tried to connect with many different Mailchimp API keys now. I’ve installed the pro version of this plugin to test on various of my sites.. Same problem always.

When hitting “Get Lists”, a red cross appears on the blue menu bar and no lists are being loaded.

I also posted on the Pro Forum but no feedback there and it’s been almost three days now.

http://voltroid.com/support/forum/topic/no-lists-appear-from-api/

https://wordpress.org/plugins/chimpmate/