One Time Tokens

When I log into my QW Tracker account, I have two one-use tokens from last year showing on my Quiz details opening page.
Although when I hover the cursor over the red cross and the message "click here to delete this token", I can not delete them, can you tell me how please?

Hi Barrie,

What happens when you try to delete them - is there any error message or problem reported?

no error message - just no response, but I can delete student submissions from the "results" okay.