Starting January 11th, 2021, all Maxon One and Red Giant Complete subscriptions migrated over from Red Giant accounts to Maxon accounts.
You will now need to sign into the Maxon App (found in your Applications folder on Mac, or Start Menu on Windows) using the Maxon option instead of the Red Giant option.
An email was sent to all users affected by this on December 16th, 2020 which included a link to setup your Maxon account.
If you are using the older Red Giant Application Manager, you can follow these steps:
1. Sign Out through the top right menu.
2a. Sign in with the Maxon option.
2b. A password reset link was sent to users affected by this change on December 16th. If you can't find that email, use the Forgot Password option when trying to sign in to reset it once more.
2c. If you get a message about your account being reserved, check this FAQ.
3. You can skip the Red Giant login screen if you are only using Maxon One or Red Giant Complete.
4. After you've signed in with your Maxon account, click Activate beneath the products if necessary (they may have automatically activated as well).
Once you've followed those steps, try the plugins in a brand new project or composition file. If there are no watermarks on the new file but they are still present in the old one, clean out the render cache of your project and you should be good to go.
If you run into any problems with this process, or have other questions, contact support.