At least you can watch on Edge for now until someone figures it out.

When I search about this error, it seems it could be related to the connection. Do you use any VPN software that might be affecting how Firefox connects to Netflix?

Good idea to try Firefox's Safe Mode. When you have a problem with one particular site, another good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, click the lock icon at the left end of the address bar. After a moment, a "Clear Cookies and Site Data" button should appear at the bottom. Go ahead and click that.

In the dialog that opens, you will see one or more matches to the current address so you can remove the site's cookies individually without affecting other sites.

Then try reloading the page. Does that help?

Hi. Thanks for your reply. Tried both clearing cache and removing site's cookies, but problem continued.

So I've backed up all my FF data, uninstalled it, deleted all FF folders, and the reinstalled the earlier version 82.0.1. Also did a Refresh.

Netflix now seems to be working. I'll hold off on allowing it to update for a while.

Thanks again.