uBlock fully disabled on Chrome? Try this fix to get it working again

If you’re a Chrome user who relies on uBlock Origin to keep ads and trackers at bay, you might have run into a roadblock in the past few hours. The extension suddenly stopped working for many people, with popups warning that it’s no longer supported. Reports flooded Reddit’s r/uBlockOrigin subreddit yesterday, where users shared screenshots of their beloved ad blocker grayed out and disabled.

This isn’t a bug or a random glitch. It’s part of Google’s bigger push to phase out older extension tech, specifically Manifest V2, which uBlock Origin depends on for its full power. Google started warning about this change almost a year ago, and many users reported the extension was being disabled in October last year. Now, the problem is back, and it’s hitting hard with Chrome version 138 and up.

The company is forcing extensions to switch to Manifest V3, a newer framework that’s supposed to be more secure but comes with limits on how ad blockers can work. Many have been pretty vocal about mentioning that it’s just Google’s way of protecting ad revenue. That said, towards the end of last year, the folks behind uBlock Origin confirmed that they’ll be ending support for the extension because of these changes. But coming back to the issue at hand, if you’re impacted by this recent change, there’s still some hope.

I spotted a workaround shared by u/SinfulYT on a post discussing the issue that has now gotten over 3K upvotes. So without wasting time, here’s what you need to do. 

Fix for disabled uBlock Origin extension on Chrome

First, open Chrome and type chrome://flags into the address bar. Search for "temporary-unexpire-flags-m137" and set it to Enabled. Restart the browser. Then head back to chrome://flags and disable these three: "extension-manifest-v2-deprecation-warning," "extension-manifest-v2-deprecation-disabled," and "extension-manifest-v2-deprecation-unsupported." Finally, enable "allow-legacy-mv2-extensions." After another restart, uBO should spring back to life. Users in the comments praised this trick, with one saying it worked like a charm on the latest build.

For those on Chrome 139, swap in the "unexpire m138" flag instead. But if you’re on version 140 or higher, flags like these are reportedly gone. You might try a command-line tweak — adding "--enable-features=ManifestV2Extensions" to your Chrome shortcut — but even the uBO team warns that’s probably short-lived. They shared a link to a GitHub discussion for details, stressing it’s not a permanent solution.

If you want a visual guide, you can even check out this helpful video posted by a uBO mod:

Don’t get too comfortable, though. These fixes are just buying time. The uBO moderators pinned a mega thread explaining the end of support, urging people to backup their custom filters and rules before the workarounds fail completely. Switching browsers is the real long-term answer for full uBO functionality. Firefox stands out as a top choice because it still supports Manifest V2 and has committed to keeping powerful ad blockers alive. Plus, it’s not tied to Google’s ecosystem.

Firefox can import your bookmarks, history, and passwords from Chrome in minutes. If you stick with Chrome, there’s uBO Lite, the Manifest V3 version. It’s lighter and blocks basic ads well, but it lacks advanced features like the full element picker for zapping specific page annoyances. The team is working on improvements, but the framework limits mean it won’t match the original.

Nevertheless, give the workaround a shot and let me know if it worked for you in the comments section below. Also, if you’re considering switching from Chrome, I’d be interested to know which browser you’re picking instead.