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 from mobile data to Wi-Fi   
*Please note that if you switch between connection types in the middle of gameplay, an error may occur.　  
Please refrain from switching between LTE and Wi-Fi connections 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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If the following conditions apply to your save data, then you will not be able to play normally or transfer data. As such, please check if they apply to your case.

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- You attempted to transfer a single instance of save data to multiple devices
- You attempted to use data restored from a backup such as device storage or cloud services
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Please also note that you cannot log in to a single account on multiple devices.