Outlook Add'in for bpm'online - Customization

We're using the Outlook Add-in, "Smartcloud Connect for bpm'online" and if you go to Settings > Customization, you should be able to add other objects to be available in the add-in. When I try to go there however, the page will not load. This is all I see:

I've tried this with Chrome, IE, Edge, always the same issue. It has actually worked on another user's Mac, yet they are the only one with a mac and everyone else like me has PCs. 

I believe this is a third party developed app, so I understand bpm may not support this. But has anyone else ran into this same issue or have any ideas how to get past the error?

Thank you!