about 4 years ago - UbiYubble - Direct link
There is ongoing maintenance with UbiClub which can result in club challenges or other club related features working as intended.

Originally posted by Mortredor: is there a place where they post maintenance schedules, or are we just expected to know by soaking in the will of the Ubi as we play?

It was announced earlier today on our Support Twitter. That's where you can find updates on server issues and any other problems you might be experiencing.