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In case none of the above resolutions are useful, then it could be a sync issue where your course (or event) from Harmony has not properly synced with the website. In such a case, raise a ticket below or have your country representative raise an issue
Anchor Cause 7 Cause 7
Cause 7 - You have announced a recurring event with registration enabled and some of the instances don't seem to show up on the website.
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