That's an unusual symptom. What URL are you using to start the login process? If that's wrong, that would explain the symptoms. I'm signed in at the moment, so I can't give you the general-purpose sign-in URL right now.
The read-me-first announcement thread at the top of the Church Account forum has solutions to most Church Account problems:
https://tech.churchofjesuschrist.org/fo ... hp?t=30383
Trying again after waiting a couple of hours might help if the problem was a momentary server issue. Clearing your browser's cache and deleting relevant cookies might help if the infamous cookie problem is in play. Trying a different computer/device and/or browser could help find a solution.
If the problem is with your account, if nothing else solves it, ask your ward/branch clerk for the contact information for the Global Services Department.