Web-bugs: www.youtube.com - see bug description

[Gravydigger]

URL: https://www.youtube.com/

Browser / Version: Firefox 81.0
Operating System: Windows 10
Tested Another Browser: Yes Chrome

Problem type: Something else
Description: Parts of the webpage keep signing me out, then flag a 405 error then signing back in
Steps to Reproduce:
When I first access the Youtube homepage (or refresh the page), everything is as it should be. However, clicking any tab on the sidebar (home, trending, subscriptions, etc.) result in the rest of the website showing the default display for a signed-out user, with a "Sign In" button at the top right. Pressing the button shows the following message:

1. That’s an error.

The request method GET is inappropriate for the URL /youtubei/v1/browse. That’s all we know.

View the screenshot

Browser Configuration

• None

_From webcompat.com with ❤️_

[softvision-oana-arbuzov]

Thanks for the report, but I'm not able to reproduce the issue. I kept on navigating between the sidebar tabs (home, trending, subscriptions, etc.), but I'm still signed in.

Tested with:
Browser / Version: Firefox Nightly 83.0a1 (2020-09-28)
Operating System: Windows 10 Pro

@Gravydigger could you try clearing cache/data/cookies, disable Ad-blocker (if available), or use a clean profile, and check again?

[Gravydigger]

I started firefox up in safe mode and also used a clean profile

(Following image was taken using a clean profile)

I do hope that this isn't an issue on my side, cause I'm not too sure where I would get further help on this :/
Any other method I could use to help figure out the issue?

[winneratwin]

check if you have a antivirus that changes the certificate/blocks web pages had the same problem had to uninstall kaspersky antivirus

[Gravydigger]

check if you have a antivirus that changes the certificate/blocks web pages had the same problem had to uninstall kaspersky antivirus

@winneratwin Thank you! It seemed that the certificate used by Kaspersky was the issue.