Troubleshooting: Triggers (activation Issues)

Error: your tag isn't firing because GTM doesn't know when to fire it. You need to find a unique "signal" on your website to activate it.

Here are the two best ways to find that signal.

Method 1: the "variable hunt" (works on any site)

This method is useful if you don't have other tags configured yet. You look directly at the raw data to find a unique signal.

Analysis

• Open Tag Assistant and navigate on your website to the page where the tag should fire.

• Select an Event in the left timeline that seems relevant (e.g., Container Loaded or a specific message like purchase).

• Click the "Variables" Tab.

• The hunt: scan the list for a variable that identifies this specific page or action. You are looking for two specific types:

  • Focus on 'Custom Event': Scan the list for a row where the Variable Type is 'Custom Event'.

    • Check the Value (Right Column): Look for a name that describes the action (like "view_item", "purchase", or "custom_product_detail").

    • Check the Variable Name (Left Column): Once you find the correct value, look at its Variable Name on the left (e.g., _event or Event). Write this down—you may need to use this specific variable name later to configure your trigger."

  • (Alternative) URL Path: If there is no specific event, look for Page Path. Does it have a unique address like "/order-confirmed"?

If you successed with the above, then, now you have the ingredients for creating your trigger.

Method 2: the "copycat technique" (best practice)

If another tag is already firing correctly on the page, you can simply copy its logic.

1. Analysis

• In the Tag Assistant timeline, find an event where a different tag fired successfully (Green Checkmark ✅).

• Click on that successful tag (e.g., "Meta Product tag").

2. Values view

• Look at the firing triggers section at the bottom of the tag details.

  • Tip: in the top right corner of the panel, switch the radio button from names to values.

• Why? This reveals the exact rule being used (e.g., _event equals custom_product_detail) instead of just the generic name.

How to fix it

Once you have identified the value (e.g., "custom_product_detail"), go to your Criteo Tag in GTM.

• Scenario A: the trigger already exists

  • Open the Criteo Tag (Purchase or View Item).

  • Scroll down to the triggering section.

  • Click the pencil icon or the center of the section.

  • Search for a trigger that uses the value you found.

  • Select it and Save.

• Scenario B: The Trigger does not exist (Create it)

  • Open the Criteo Tag and click on the Triggering section.

  • Click the "+" (Plus) icon in the top right corner to create a new one.

  • Name it: give it a clear name (e.g., "Trigger - Custom Product Detail").

  • Trigger configuration:

    • If you found an Event: choose Custom Event. Paste the exact name you found (e.g., custom_product_detail) into the Event Name field.

    • If you found a URL: choose Page View. Set it to "Some Page Views" and enter the condition (e.g., Page Path contains /order-confirmed).

  • Save the trigger. It will automatically be added to your Criteo Tag.