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Debug and Solutions

Common Issues

Tag Not Firing

Symptom

The Probr Listener tag does not appear in GTM Preview mode, or appears with the status "Not Fired".

Causes and Solutions

Cause Solution
Missing trigger Verify that the "All Events" trigger (or your custom trigger) is attached to the tag
Tag paused Check that the tag is not paused in GTM
Version not published Publish a new container version
Client-side container The tag is designed for server-side containers only. Verify you are in the correct container

Tag Fires but No Data in Probr

Symptom

In Preview mode, the tag shows "Succeeded" but no data appears in the Probr dashboard.

Checks

  1. Correct endpoint?

    • Verify the URL in the tag configuration
    • Test with curl:
    curl -X POST https://api.probr.io/ingest \
  -H "Content-Type: application/json" \
  -H "X-Probr-Key: YOUR_KEY" \
  -d '{"container_id":"test","event_name":"test","timestamp_ms":0,"tags":[]}'
    • You should receive {"status": "ok"}

  2. Correct API key?

    • Verify the key matches the site in the Probr dashboard
    • Check it hasn't been revoked

  3. Firewall / network?

    • If your sGTM is behind a firewall, verify that outbound requests to api.probr.io (port 443) are allowed

  4. Preview vs Production mode

    • GTM Preview mode can sometimes behave differently from production
    • Also check in production (wait a few minutes after publishing)

"send failed (4xx)" Error in Console

401 — Unauthorized

The API key is missing or invalid.

Solution: check the "Probr Ingest Key" field in the tag configuration.

403 — Forbidden

The key has been revoked or the site is disabled.

Solution: go to Probr dashboard > Sites > check the site and key status.

429 — Rate Limited

You are exceeding your plan's requests per second limit.

Solutions:

  • Switch to batched mode to reduce the number of requests
  • Upgrade your Probr plan
  • Check that you don't have multiple Probr tags firing on the same event

Tag Names Not Showing in Dashboard

Symptom

The dashboard shows "tag_15", "tag_22" instead of actual tag names.

Cause

Tag metadata is not configured in GTM.

Solution

For each tag in your container:

  1. Open the tag in GTM
  2. Advanced Settings > Additional Tag Metadata
  3. Check Include tag name
  4. Publish a new version

user_data Always Shows False

Symptom

The dashboard shows 0% email/phone/address presence even though you are sending this data.

Possible Causes

  1. Data sent in wrong format The tag checks the standard GA4 path:

    user_data.email_address
user_data.phone_number
user_data.address.first_name

    If your data is at a different path (e.g., user.email), it won't be detected.

  2. Data missing server-side The sGTM client (GA4, custom) may not be transmitting user_data in the event data.

    • Check in Preview mode, Event Data tab, that user_data is present

  3. Consent not granted If your CMP blocks sending user_data without marketing consent, the data won't be present in events without consent.

E-commerce Data Always Empty

Symptom

E-commerce metrics are all at 0% even though you have purchases.

Cause

The tag only checks e-commerce data on these events:

  • purchase
  • begin_checkout
  • add_to_cart
  • add_payment_info

If your events use different names (e.g., buy, checkout), e-commerce data won't be checked.

Solution

Use standard GA4 event names.

Batched Mode: Data Lost on Restart

Symptom

"Gaps" in data, often correlated with Cloud Run instance restarts.

Cause

The batch buffer is stored in templateDataStorage, which is in-memory per instance. When an instance is terminated (scale down, redeployment), the unsent buffer is lost.

Solutions

  1. Reduce batch size so flushes happen more frequently
  2. Switch to per-event mode if data loss is unacceptable
  3. Stabilize your instances: configure a minimum instance count > 0 in Cloud Run (or equivalent)

Tag Slowing Down My Container

Symptom

Increased response time for the sGTM container after adding the Probr tag.

Short Answer

The Probr tag does not slow down your container. It calls data.gtmOnSuccess() immediately, before data is even sent. The HTTP request is made non-blocking in the addEventCallback callback.

If You Still Observe Slowdown

  1. Check if the slowdown is caused by another tag added at the same time
  2. Check latency to the Probr endpoint (should be <100ms)
  3. In batched mode, templateDataStorage adds a read/write operation, but its impact is negligible (<1ms)
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