Live Chat plugin not displaying correctly

Good Afternoon,

I've just installed the Chat plugin, however when I click on it, it doesn't fully pop up so no chats can be started. This happens in all browsers.

I've tried uninstalling all other plugins but the same still happens. I've also tried the solution offered here, but this made no difference. When I click Inspect Element in Chrome however, the window opens. There are some errors in the Console but I'm not sure if they're relevant. I've included some screenshots.

The link to the site is

Please let me how this can be fixed.