Coty: We have been informed that the game can play on Windows 8 (as can Ignite) but some users do have issues. This wouldn't cause the "Failed to Connect" issue however. The fact that your friend can get in may just mean that he has a better connection and can connect before the other users trying to log in, or that he is lucky.
pr_firedragon, Mr.GreenBeans, josejmb93, el_negro: We have talked to Joymax about the IP restriction for Puerto Rico, and they have assured us that your specific IP addresses are not blocked. While we have them look at the bigger issue, they have requested that you try to contact your ISP (Internet Service Provider) and and ask for assistance connecting. If they ask what IP you are trying to connect to, tell them digimonmasters.aeriagames.com
We can suggest an AFK kick timer, I know other games have had it.