I'm having trouble creating Trello board in CRM

I'm having trouble creating Trello board in CRM

HI,

I have installed Trello in CRM but when I try to create a board, it loos as though it's going to create it and then it doesn't.
I have read the guide provided and can't see where I'm going wrong.
Am I missing something? can someone advise me?

I have done this through CRM and haven't used any other apps such as flow as I didn't need to.

Thanks,

Cate.