このエラーメッセージに関する原因と対処に関して説明します。
エラーメッセージ(英語)：
sync not working
対処
関連リンク
aws s3 sync not working as expected - Stack Overflow
https://stackoverflow.com/questions/27967133/aws-s3-sync-not-working-as-expected
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https://stackoverflow.com/questions/46683819/cross-account-sync-not-working
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https://stackoverflow.com/questions/35193275/s3cmd-sync-is-working-but-not-aws-s3-sync
aws s3 sync not working for restored glacier objects ・ Issue #3250 ...
https://github.com/aws/aws-cli/issues/3250
AWS Developer Forums: Tag: cognito_sync
https://forums.aws.amazon.com/tags/cognito_sync
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https://devcentral.f5.com/questions/gtm-config-sync-not-working
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https://trac.cyberduck.io/ticket/8533
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https://www.reddit.com/r/pokemongo/comments/9usdj8/adventure_sync_not_working/
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https://forums.att.com/t5/Wearables/Number-sync-not-working/td-p/5471420/page/2
Samsung Gear and Strava ? Strava Support
https://support.strava.com/hc/en-us/articles/218887007-Samsung-Gear-and-Strava?page=3