Hello there @9hN please accept my apologies for this issue. Could you please try opening your main profile in guest mode to see if you do not receive this error when accepting cookies? You can open a Guest Window by going to Main menu --> Open Guest window.
Also please try disabling shields to see if this is the reason why you are unable to accept cookies.
@9hN If the page properly works in guest mode, please try changing your cookies blocking settings on shields to only block cross-site cookies to see if this allows you to accept them on your main profile.