Why GA4 sometimes doesn’t save events – and how to find the error

Tracking errors are not only frustrating, they also cost valuable insights. This article is aimed at marketers and developers who want to track GA4 events accurately. Learn how to identify and correct event errors and make your tracking data reliable – for complete marketing analytics.

• Tracking marketing success? Essential! But what if GA4 doesn’t play along?
• Step by step: How to find errors in GA4 events
• Step 1: How can I tell if an event has been saved correctly?
• Step 2: Retrieve the faulty event payload from the matelso push logs
• Step 3: Find errors in the API response
• Step 4: Fix the error and test the event again
• Conclusion: No more lost events in GA4!

Many of our customers want to evaluate their online marketing measures precisely. A key KPI here is the number and quality of contacts generated by campaigns.

If, in addition to the automatically generated events, we also want to assign interactions that did not take place directly on the website—such as calls or transactions—we use the GA4 Measurement Protocol. This makes every touchpoint measurable. However, there is a problem in practice: minor errors occasionally prevent events from being accepted in GA4 at all.

The problem: No error message!

GA4 only confirms receipt of events with a 204 No Content response. This means that the response we receive from Google Analytics does not tell us whether the submission was accepted or not.

The solution?

The GA4 Validation Endpoint! This allows you to test for yourself whether your event payload is correct or why it is not appearing in GA4.

Before we start debugging, let’s check whether the event appears in GA4 by default.

There are two ways to do this:

1. Engagement reports:

• In GA4, navigate to Reports > Engagement > GA4 Events.
• Is your event name visible here? If so, it has been recorded!
• The event will only appear in this list if it was first received more than 48 hours ago.

2. Real-time report for live testing:

• If the event was sent recently, open Reports > Real-time.
• This view lists events from the last 30 minutes.
• Is the event not displayed here during your tests? Then there is a problem.

If your event does not appear, we will proceed to the next step.

Since the matelso platform sends GA4 events via Measurement Protocol, you can see exactly which events have been transmitted in the push logs.

You can test this payload now!

Send the payload to the validation endpoint using a tool such as Postman:

This allows Google Analytics to check whether the request is correct or contains errors.

Suppose you found the following event payload in the matelso push logs:

At first glance, this payload looks correct. However, when you send it to the validation endpoint, you may receive the following response:

What does this mean?

• The value for value is “00” (a string).
• However, GA4 expects a number here (e.g., 0 or 50).

Based on the error message, we change the payload:

The event is now saved correctly in GA4!

If you encounter further problems, repeat the test with the validation endpoint until no more errors occur.

Thanks to the combination of automatically recorded events in the matelso push logs and the GA4 Validation Endpoint, you can quickly find out why a custom event or recommended event does not appear in GA4.

What the Validation Endpoint offers you:

• Clarity about possible formatting errors
• Direct instructions for troubleshooting
• Faster implementation without lengthy troubleshooting