One of the two following reasons can cause Error 001004:
- Another device is already using your account.
- You have restored your account from a backup application such as iTunes or iCloud.
To fix this error, delete and reinstall Dragon Project and then try logging in again.
If the issue persists, chat with us in-game (top-right corner of support screen) or contact Customer Support and provide the following details:
- Hunter ID
- Hunter name and level
- Answer to your secret question
- Last log-in date and time