The ARMS Global Testpunch Demo was released for quite a while and last weekends servers began going live for around two hours a day.
Whilst servers are down, the demo doesn’t really do much. Players can look at each playable characters and set different arms, but they won’t be able to enter the "Warm-Up" practice mode.
This has now changed as Reddit user NefariousSquid discovered a workaround that lets players enter the practice mode whilst servers are down.
1. System Settings > Internet > Internet Settings > (Internet network) > Change Settings
2. Enable Proxy Settings and change the server address to "1.1.1.1", save
3. Launch ARMS Global Testpunch
4. Select a character and hit "+" to enter warm-up
Each session will last a little over two minutes until an error message pops up, but you can always go back in and try a different character. Enjoy!