I was not sure about that syntax. Thank you.
In this case, what would cause this error? When clicking on this link (I am sending my own custom email instead of the automatic system-generated one): https://api.backendless.com/APP_ID/USER_OBJECT_ID/users/confirmation
{"code":3051,"message":"Confirmation failed","errorData":{}}
This error is shown in plain text in the browser. The user has not already clicked the link and their userStatus remains DISABLED.
I found reference to another person having the same issue but cannot find that error code in your docs.