I can't seem to log onto You Tube to upload a video. The sign-in window won't pop up. Any ideas on remedies?

I have a Google account. I have a username and password. I just don’t get the sign-in window no matter how many times and how many ways I click on “sign in”. I’ve tried unlinking Google and You Tube (doesn’t help). I’ve tried making a new Google account (still doesn’t work). Help!