# Possible Reasons for Sync Failure
If your issue is not listed, you can click here to consult customer service.
# 1. "iCloud Storage Full" Prompt
In this case, you need to expand your iCloud storage or clear unnecessary content in System Settings -> iCloud -> Manage Storage.
# 2. "Rate Limit" Prompt
Wait for some time and try again.
# 3. "Network Unavailable" Prompt
Try switching to 4G or Wi-Fi for manual backup, or restart the device and retry.
# 4. "User Manually Deleted Cloud Data in Settings"
- Use the 'Export Database' function to save data locally;
- Uninstall and reinstall the iCost App;
- Import the database file saved locally beforehand.