The email address is the one associated with your account at the Affinity Store (store.serif.com or affinity.serif.com/store) and the password for it. It is not the email address associated with these forums (forum.affinity.serif.com).
You may use the same email and password for both, or you may have different emails, same email but different pasword, or a forum account and no Store account at all.
And if you are letting a password manager fill this in for you, it might be choosing the wrong one. (That happened to me on my iPad, where the facial recognition and automatic fill-in chose the wrong account.)
It seems that the problem is caused by special characters in your account password.
Try generating a new password with non accentuated characters and numbers and it should work.
There is another topic about that here :
Hi @276ccm,
Thanks for the info. I've replicated what you are experiencing and looking into a solution. Please give me a moment to sort a few things out and I will get back to you.