Unable to login - "No Connection Reload"

I have recently installed Gramps Web via a droplet on DigitalOcean.

The login worked well and I have added a number of entries successfully.

I tried to login again today and now at the login screen it appears to attempt to display the login screen however I am presented with a screen showing “No Connection” with a “Reload” button. Clicking the button just displays the same screen.

I can access the console in DigitalOcean.