Meta’s “Events from the Server Are Not Deduplicated” Error – What Went Down and Why It’s Resolved

Meta’s “Events from the Server Are Not Deduplicated” Error – What Happened and Why It’s Resolved

Overview

If you manage Meta ads and track conversions, you may have noticed this alert in Events Manager or Ads Manager. It might have caused some concern—or perhaps you overlooked it, expecting it to resolve itself. Either way, here’s the update: Meta has addressed the issue. No action is required on your part, and your setup wasn’t actually broken.

However, this type of tracking error can raise questions about reliability. Below, I’ll explain what occurred, how deduplication functions, and steps to verify your tracking if needed. Recently, many Meta Ads users encountered an unusual error over the weekend:



“Events from the Server Are Not Deduplicated.”

If you manage Meta ads and track conversions, you may have noticed this alert in Events Manager or Ads Manager. It might have caused some concern—or perhaps you overlooked it, expecting it to resolve itself. Either way, here’s the update: Meta has addressed the issue. No action is required on your part, and your setup wasn’t actually broken.

However, this type of tracking error can raise questions about reliability. Below, I’ll explain what occurred, how deduplication functions, and steps to verify your tracking if needed.

What Is Deduplication and Why Is It Important?

Deduplication is a process Meta uses to manage conversion events sent from both the browser (Pixel) and the server (Conversions API, or CAPI).
Here’s how it works:
- If the same event—identified by its event_id—is sent from both sources, Meta records only one instance.
- If an event comes from just one source, it’s kept as is.
- This ensures your conversion data isn’t counted twice, maintaining accurate reports. The recent error, however, appeared even in setups with no duplicates, pointing to an issue on Meta’s end rather than a user mistake.

Who Was Affected?
This issue primarily impacted brands that:
- Use Conversions API (CAPI).
- Recently transitioned from Shopify’s CAPI to another server-side tracking solution within the last 30 days.
If your setup combines browser Pixel and server-side tracking—a common practice since iOS 14 updates—you were more likely to see this notification.

What Caused the Issue?
- Based on available insights, Meta experienced a temporary glitch in processing deduplication for events linked to Shopify’s Native CAPI, including setups recently switched to other systems.
- As a result, events were incorrectly flagged as “not deduplicated,” despite no actual duplication occurring. Fortunately, this was only a visual error in the interface—no data was misreported.

How to Confirm Your Tracking Is Working

To ensure your events are tracking correctly, follow these steps:

Open Events Manager.

Review Purchase events from the past 7 days.

Compare the event total with your Shopify order count for the same period.

Note: A minor discrepancy of 5-10 orders is typical due to time zone differences. Significant gaps, however, may indicate a tracking issue worth investigating.

Troubleshooting Persistent Errors

If the error has disappeared, no further action is needed. If it persists, check for additional sources sending events to Meta:
- Is a Google Tag Manager (GTM) tag active?

- Is Shopify’s Facebook Data Sharing setting still enabled?

- Are any third-party tracking tools connected?

In Events Manager, under Purchase Event:
- A single green line (server-side) means everything’s fine.
- Both green (server) and blue (browser) lines for the same purchase suggest an extra data source may need adjustment.

Meta has resolved this issue, but it highlights the value of routinely reviewing your tracking configuration. Even minor changes, such as switching server-side tools, can trigger unexpected alerts.
Moving forward, if you encounter a similar tracking error, start by verifying your purchase event totals before taking further steps. For setups using both Pixel and CAPI, confirm that deduplication is functioning as intended.

For further information, please visit our article here: [Purchase Event from the Server are not Deduplicated in Facebook Event Manager]()

Updated on: 18/03/2025