Challenges and rewards are currently disabled
for Rainbow Six: Siege
They have been disabled as part of the transition from Ubisoft Club to Ubisoft Connect between October 21st 2020 and October 27th 2020.
Progress on started challenges will unfortunately be lost.
Rewards will be available after the maintenance on October 27th 2020 and brand-new Ubisoft Connect Core Challenges will be available with a future update.