I always log onto my key Krud14 on this computer (or any other key i own) after opening Byond. Then, i tried first to log into the game Dragon Universe X into my saved file but cannot access it. Ever. I tried redownloading BYOND, restarting my computer, and running BYOND as administrator, but none of those work. This problem also occurs with other games, like Naruto Final Fight. The only account I actually have access to on these games is the Guest account.
You have a firewall interfering with BYOND. Make sure all your firewalls are configured to allow incoming and outgoing traffic for the BYOND apps, and any hash or version checking is disabled.