Cannot Register Account

Just purchased the plugin, however, it will not allow it to be authenticated. A system check says “Everything appears in order”, however any attempt to enable sync or Check Account Data results in the word ‘Error:’ appearing in red beside the button. I cannot access any of the configurations for the plugin – they are still grayed out. Contacted support several times over the past few hours.

The page I need help with: [log in to see the link]