What is this error - "You're using an unsupported command line flag"

[Noik]

So I have been receiving this error the last four days and it keeps recurring every time I launch cent browser for the first time. I have attached screenshot below. 

What exactly is this error and how to solve it? Plz help.

   

[Дмитрий Сакович]

Hi! Message says that You have activated the command line flag --disable-set-isolation-trials need to disable it to appear this error on YouTube. I do not know how you have it activated in the start shortcut or in the settings. Check out for a start here: chrome://settings/cbOtherOptions

[Admini]

This means the flag still works, but it is not recommended because of side effect.(Or it may be removed in future version)