The ID (or email address) field in the SQUARE ENIX Account Management system is case sensitive. It's possible during registration, the virtual keyboard auto-capitalized a word after a period. For example, your email might have been registered as "Yourname@email.Com" or "yourname@email.Com" (with the "Y" or "C" capitalized). Please try entering your email address in these formats if it is not being accepted. If you are still experiencing issues with this formatting, please contact us for additional assistance.