Can't sign into youtube from iMovie - Sign in with Google disabled

Google is telling you that its updates to its online uploader have not kept pace with Apple’s new software updates. The issue is Google’s, not Apple’s.

The most reliable way to upload videos to You Tube is to share out the movie to your desktop and from there drag it into You Tube’s upload window. That was the best way even before the updates.

— Rich

The answer is an external drive. If you work with videos, you really need to get one.

Check out the Western Digital My Passport 2TB drive for $59.99.

https://www.bestbuy.com/site/wd-my-passport-2tb-external-usb-3-0-portable-hard-drive-with-hardware-encryption-black/6203245.p?skuId=6203245

There are lots of others out there sold by various vendors at various prices. I have the above drive for my Time Machine backups and a couple of 4TB drives of double backups and storage of my iMovie libraries and all my other files.

Format the drive Mac OS Extended (Journaled) or APFS and you can store your iMovie library and Photos library on it.

-- Rich