Here is a step-by-step guide on how to fix the "Server sending modified fbclid value" error on your Shopify store. This process doesn't require any coding and focuses on the most common solutions.
Step 1: Re-verify Your Data Sharing Settings in Shopify
This is the most likely cause of the issue. You need to ensure Shopify is sending the most complete data possible to Meta.
Log in to your Shopify admin dashboard.
In the left-hand menu, click on "Sales Channels" and select "Facebook & Instagram".
On the Facebook & Instagram page, click on "Settings".
Scroll down to the "Data sharing settings" section.
Confirm that the data sharing level is set to "Maximum".
If it is already "Maximum", a quick fix can be to toggle it. Change it to "Enhanced", click "Save", and then immediately change it back to "Maximum" and "Save" again. This "resets" the connection between Shopify and Meta.
Step 2: Enable Automatic Advanced Matching in Meta Events Manager
This step won't fix the server-side error directly, but it significantly improves your conversion attribution and can help Meta identify customers even if the fbclid is missing.
Go to your Meta Ads Manager and open the Events Manager.
In Events Manager, select your Meta Pixel from the data sources list.
Click on the "Settings" tab.
Scroll down until you see the "Automatic Advanced Matching" section.
Make sure the toggle switch is turned ON.
Click on "Show Customer Information Parameters" and ensure all the available fields (like Email, Phone number, First name, etc.) are also toggled ON.
Step 3: Check for Conflicting Apps on Shopify
This is a troubleshooting step if the first two don't resolve the issue. A newly installed app might be interfering with the data flow.
In your Shopify admin, go to the "Apps" section.
Review your list of installed apps. Look for any apps related to:
Third-party analytics or conversion tracking.
Caching or page speed optimization.
Marketing or affiliate tracking.
If you have recently installed one of these, try disabling or uninstalling it temporarily to see if the Meta error goes away.
Step 4: Use the Meta Event Testing Tool (Optional, but Recommended)
This is a great way to confirm if your server is now sending the correct data.
In your Meta Events Manager, go to the "Test Events" tab.
Click on the "Test Server Events" section.
Follow the instructions provided by Meta to send a test event from your server.
Look at the event details in the testing tool. You should see a parameter called fbc being passed along with the event, and the value should be a long string of numbers and letters, not a truncated or modified version. This confirms your fix is working.