Please note that you may experience errors if you are attempting to play the game within an unstable network environment.
In such cases, please try the following troubleshooting steps:

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    - Switch connections between mobile data and Wi-Fi
      *Please note that if you switch between connection types in the middle of gameplay, an error may occur.
　     So please refrain from switching between LTE and Wi-Fi connection while playing the app. Please close the app first, then switch your connection type and confirm if it resolves the issue.
    - Upgrade the speed/data limit or service of your Mobile Data
    - Confirm if there are any issues with the Wi-Fi modem and router, and restart the devices
    - Confirm if the Wi-Fi router is properly connected to the Internet
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In addition, if the following conditions apply, the relevant game data would be the one that you are unable to play normally or perform Data Transfer with.
As such, please check if they apply to your case.

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   - Attempt to perform Data Transfer for the same gameplay data on multiple devices
   - Data was restored using backup data from the device storage or Cloud services
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Please also note that a game account cannot be logged in on multiple devices.