It’s not uncommon to see a website getting broken in Chrome Canary, recently Chromium developers have broken the YouTube for the second time in this year by enabling deprecated HTML Imports, as a result of that, YouTube site looked zoomed-in or distorted. The issue has been fixed by Google in Chrome 80 Canary, but the issue can still be seen in Microsoft Edge Canary 80 and in coming days in Edge dev, here is how you can make the YouTube work again in new Microsoft Edge browser.
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Unfortunately, running Edge with “– disable blink features=HTMLImports” flag isn’t fixing the issue and changing the User Agent in developer tools, also not helping.
You can fix this issue by changing user agent of Chromium Edge to Firefox, as developer tools way of changing UA not working, you need to install an extension for that, read on below for the necessary steps you have to follow.
Fix broken YouTube in Microsoft Edge Chromium
1. Ensure you’ve set Edge to allow extensions from other web stores at edge://extensions page,
2. Visit User-Agent Switcher and Manager extension page in Chrome Web Store and install the extension
3. Click on extension icon on toolbar, click on drop down arrow and choose Firefox, and make sure Firefox 69.0 is selected, click “Apply”.

4. Now To make Firefox as user agent for YouTube site only, click on extension toolbar icon > Options, choose “Whitelist mode” and type “youtube.com” (without quotes), scroll down and click “Save” button
Now visit YouTube, it will load just fine, once the issue is fixed, remove the extension.
