[WIKI] Explain how to use uBlock Origin / enable MV2 in Chrome 139-140

[I-I-IT]

Chrome 139 disables support for Manifest V2, but there is a workaround, which also works in Chrome 140.

For Chrome 139

1. Restore old flags with

chrome://flags/#temporary-unexpire-flags-m137
chrome://flags/#temporary-unexpire-flags-m138

1. Enable
   chrome://flags/#allow-legacy-mv2-extensions
2. Optionally, disable the depreciation warnings

chrome://flags/#extension-manifest-v2-deprecation-warning
chrome://flags/#extension-manifest-v2-deprecation-disabled
chrome://flags/#extension-manifest-v2-de precation-unsupported

For Chrome 140/ when upgrading to Chrome 140 (the extension will become disabled, and you will need to do the steps below to reactivate it - I am not sure if the data is wiped or not, since I don't use Chrome Canary often. Make a backup just in case).

1. Restore old flags

chrome://flags/#temporary-unexpire-flags-m138
chrome://flags/#temporary-unexpire-flags-m139

2. Enable

chrome://flags/#allow-legacy-mv2-extensions

[nicolaasjan]

I had no success with these flags...
(Chrome dev build 140.0.7264.0)

Commandline parameter works.
chrome --disable-features=ExtensionManifestV2Unsupported,ExtensionManifestV2Disabled
See here.

[I-I-IT]

I just tested and you can not load new extensions but you can still use ones that were installed before. I guess that's why it still works with that flag.

[TheSimArchitect]

Thanks! I had to do both, the flag and the command line. 🌻

[nicolaasjan]

Command line parameter still works for Chromium dev. build 141. 😀️

[Dum4G]

142 still has those arguments, lets go!

[nicolaasjan]

142 still has those arguments

143 (dev build) as well. 😀️

[ademdemirtas]

No it not working for 139

[ademdemirtas]

Loaded but not activated! Could it be because it is not listed in the store?

[I-I-IT]

7day block? Can you share screenshots?

You also can just clear cookies / open in private tab (make sure uBo is enabled in Private Mode)

[ademdemirtas]

As you said. Youtube does not use it! Peer comes like a black curtain, I can't close it.

[I-I-IT]

You might have a malicious extension or program. This doesn't look like official YouTube Button.

[ademdemirtas]

So what should I do to find this

[I-I-IT]

Check your extensions list in chrome://extensions.

Try removing one extension by one extension, then restart browser and see if this warning on YouTube still appears. If it still does, also try reinstalling uBlock Origin from the Github Releases Page.

[aleks747]

Спасибо большое! Помогло

[Yuki2718]

FYI if your default browser is Chrome and you want to apply the command-line option whenChrome is opened on click of a html file, you can insert the command in HKEY_CLASSES_ROOT\ChromeHTML\shell\open\command like this screenshot.

Screenshot