Hello @Exodus-_ thanks for getting in touch with us.
If you have Rainbow Six Siege purchased on two separate platforms, progress is also shared between all PC platforms, so whatever you have unlocked on the Ubisoft Connect version of the game, will also unlock on Steam, if using the same Ubisoft Account to log in to each game,
The Steam game you redownloaded is already tied to a Ubisoft Account you have. If you see the 'problem authenticating' message, you may be logging in to the game with an incorrect Ubisoft Account.
To help you find the correct details you need for your Steam version of the game, get in touch with us through our support channels for further help locating your correct details >
Ubisoft Support Website - https://www.ubisoft.com/en-gb/help/contact
Twitter Support - https://twitter.com/UbisoftSupport
Facebook Support - https://www.facebook.com/UbisoftSupportUK/
Please gather as much of the following information as possible as this will make it easier to locate your account when you contact us on the links above >
- Name of game you are trying to access
- Any Ubisoft usernames you have used in the past
- Any email addresses you may have used on your Ubisoft account
- Your Steam unique ID code
- A screenshot of your ownership file located here by default >
C:/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/cache/ownership
We then use this information to try and help you locate the correct details you need to sign in.