"Event parameters blocked" in Meta Events Manager: should I unblock them?

What the block covers

Meta's instruction for this diagnostic is to "review the parameters and fix issues with the data you're sharing. Then, request to unblock fixed parameters or tell us to keep blocking them in Meta Events Manager." Each parameter gets its own decision.

• Blocked: the parameters listed in the diagnostic. Meta says "If you block a parameter, you won't be able to send or use it in features like custom conversions and custom audiences."
• Still arriving: your events and the parameters that aren't on the list.
• Possibly for good: "You may not be able to unblock parameters that are blocked by Meta."
• Knock-on effects: a custom conversion or audience built on a blocked parameter loses that input. If it was built on a value that names a condition, it may be flagged too. See flagged custom conversions and flagged custom audiences.

How to review blocked parameters

You need full control permissions on the business asset. If a developer maintains your site, Meta notes you may need their help to review what you're sending and change your setup.

1. Go to Meta Events Manager and click Datasets in the left menu.
2. Select the name and ID of your dataset, then click the Diagnostics tab at the top of the page.
3. Find the diagnostic message that says Event parameters blocked and click Review.
4. Read the acknowledgement. It reminds you that "you cannot share sensitive or otherwise prohibited information." Click I acknowledge.
5. Open the Action required tab to see which parameters are blocked. For each one, check its name and the values it has been sending, then choose to unblock it or keep blocking it.

Unblock or keep blocking: how to decide

Meta gives three reasons to keep blocking a parameter: you're "unable to review and fix the parameter now", you "can't confirm that the parameter only shares data which follows the Meta Business Tools terms", or you "want to avoid the parameter causing further data restrictions." If none of those apply because the parameter has been fixed at its source, it is a candidate to unblock.

On a clinic or telehealth site, start with parameters that carry a service, treatment or answer rather than a technical value: a content name copied from a treatment page, a custom property holding the service a visitor booked, a quiz or intake answer, or a form field captured by a tag. Ask what the parameter is for. If its whole value to you is the condition it names, fixing it means no longer sending it, and it should stay blocked.

Unblock when the source has changed, not when the parameter seems probably fine. Meta's warning applies after you unblock: "If further issues are detected, your data may be restricted and functionality in certain ad features may be limited."

Why repeat notices matter

Meta says: "If you receive these notifications multiple times, Meta may restrict you from sharing certain data, such as custom parameters and parts of URLs after the domain, by placing your Meta Business Tool into a core setup for at least 90 days." Core setup removes every custom parameter, not just the one that was blocked, so unblocking a parameter that still carries the same values risks far more than it gives back. See what still works under core setup.

What not to do

• Don't rename the parameter, move its value into another field or send it server-side instead. Meta says "You must not attempt to send data that has previously been detected and removed." See server-side tracking, renaming and Meta restrictions.
• Don't unblock a parameter to rescue a custom conversion or audience that depended on it. If that feature was built on a condition, it is next in line to be flagged.
• Don't treat the block as Meta handling compliance for you. Meta says "You are ultimately responsible for the data you share with Meta."
• Don't read this notice alone. If you also received one saying "potentially prohibited information was removed", see what to do when Meta removes potentially prohibited information, which covers where to look across your whole site.

Talk to Curve

Blocked parameters are a warning that can escalate to core setup, and the fix lives in what your site sends. Curve's team will go through your parameters with you, show what's likely triggering the block, and rebuild your tracking server-side with PHI-like patterns detected before data reaches Meta. To get ahead of the next notice, book a call with Curve.

Frequently asked questions

Sources

• Meta Business Help Center: How to review blocked parameters in Meta Events Manager
• Meta Business Help Center: Troubleshoot Meta Business Tools prohibited information notifications

Last verified September 29, 2026

Related pages

• Meta Removed Potentially Prohibited Information: Next StepsWhat Meta's prohibited information notice means for a health business, where to find what was removed, how to fix it, and why you must never re-send it.
• Meta Core Setup for Health Businesses: What Still WorksMeta core setup strips custom parameters and everything after the domain. What still works for a health business, why it happened, and what to fix first.
• Meta Flagged My Custom Conversion for Health InformationWhy Meta flags custom conversions that suggest a health condition, what the flag does to running campaigns, and how to rebuild or request a review.
• Meta Flagged My Custom Audience or Lookalike: Next StepsWhy Meta flags custom and lookalike audiences that reference a health condition, what the flag stops, and how to fix the seed or request a review.
• Meta Blocked My Custom Events Until I Review ThemWhy Meta blocks every custom event once a dataset has data restrictions, which events to confirm, which to keep blocked, and why renaming is not a fix.
• Does Server-Side Tracking Get Around Health Restrictions?No. Meta restricts health data by data source, not by route, and forbids re-sending removed data. Here is what server-side tracking is really for.