First: did it stop working suddenly, around August 2026?
If your features" class="doc-internal-link">ad blocker was working fine and then simply stopped — no settings changed, nothing you did — check this before anything else on the list below, because it isn't a fault on your end and none of the usual fixes will help.
Chrome and Edge have both retired Manifest V2, the older extension platform. Chrome disabled it in Chrome 138 (July 2025) and removes the last MV2 extensions from the Chrome Web Store on 31 August 2026. Edge began its own phase-out in August 2026, finishing for most users by the end of the year. Any blocker that never migrated to Manifest V3 gets switched off as part of that.
How to tell that's what happened:
- Your browser showed a notice about an extension being turned off, or the
extension is greyed out at
chrome://extensions/edge://extensions - It disappeared from the store, or shows as "no longer available"
- Reinstalling doesn't help, and the allowlist/enabled checks below all come back clean
If that's the situation, the fix isn't a setting — it's an extension built for Manifest V3. For uBlock Origin specifically, the MV3 version on Chrome and Edge is uBlock Origin Lite, which is deliberately more limited. If keeping the full version matters more to you than the browser does, Firefox and Brave both still support it — Brave hosts MV2 extensions on its own servers. See What is Manifest V3 for the full timeline.
Common Reasons Your Ad Blocker Isn't Working
1. The Site Is Allowlisted
You may have previously allowed the site. Check your ad blocker's allowlist and remove the site.
In DNDShield: Click the shield icon → check if the site is allowed → toggle protection on.
2. Native/Sponsored Content
Some "ads" are actually native content — articles or recommendations that are part of the site's HTML, not loaded from ad servers. These are harder to block because they look like regular content.
Examples: "Sponsored" articles on news sites, "Promoted" posts on social media.
3. The Ad Blocker Is Disabled
Check if the extension is enabled:
- Chrome: Go to chrome://extensions and verify it's toggled on
- Edge: Go to edge://extensions
4. Outdated Filter Lists
Ad blockers use filter lists that need regular updates. If your lists are outdated, new ad formats may slip through.
In DNDShield: filter rules are compiled into the extension itself rather than fetched in the background, so they refresh when the extension updates. Browsers apply extension updates automatically, so in practice there's nothing to do — but if you've been running the same version for a long time, check for an update rather than assuming the lists moved on without it.
5. Anti-Ad-Blocker Scripts
Some sites detect ad blockers and show a popup asking you to disable it. The site may also show different ads that bypass your blocker.
Fix: Use an ad blocker with anti-detection features, or try refreshing the page.
6. First-Party Ads
Some websites serve ads from their own domain (first-party ads). These are harder to block because blocking the domain would break the entire site.
7. Multiple Extensions Conflicting
Running two ad blockers can cause conflicts. Use only one ad blocker at a time.
Quick Fix Checklist
- Is the extension enabled? (chrome://extensions)
- Is the site allowlisted? (check ad blocker settings)
- Try refreshing the page (Ctrl+Shift+R for hard refresh)
- Update filter lists if available
- Try disabling other extensions to check for conflicts
- Reinstall the ad blocker as a last resort
FAQ
Why do I see "ad blocker detected" messages? Websites use scripts to detect ad blockers. Modern ad blockers block these detection scripts too, but some sites update their detection methods frequently.
Can websites force me to disable my ad blocker? No. Some sites block content until you disable it, but you can choose to leave the site instead. DNDShield's temporary allow feature lets you view the content without permanently disabling protection.
My ad blocker stopped working completely after an update. What happened? If this was on Chrome or Edge around August 2026, it was most likely the Manifest V2 shutdown rather than anything on your end — browsers switched off extensions built on the old platform. See the section at the top of this page.
Do I need to switch browsers to keep my ad blocker? Only if you specifically want a Manifest V2 extension like the full uBlock Origin, which Firefox and Brave still support. Anything already built for Manifest V3 keeps working on Chrome and Edge as normal.
Site still shows a "please disable your ad blocker" wall? See Undetectable Ad Blocking — how DNDShield defeats the scripts that put up those walls in the first place.