Friend of mine wrote me that she can't get into her Dynadot account for a few hours already. All she gets is reloading Dynadot home page with new captcha code.
I, in my turn, can log into my Dynadot account without any issues, so it looks kind of strange.
There is a login issue for some users. You should be able to log in now, but the problem might reoccur. We should have a permanent fix for this by the end of the day tomorrow.