Apparently I need to be connected to the internet to access the daily shallenge...Obviously my PC is connected as soon as it boots up. Does this happen to anyone else ?

This started happening after "The End is near" update..

I've been trying to find a support system on motiontwin.com in order to submit a ticket but it doesn't seem to exist

I saw your post and tested, and even before "The End is Near" update I can no longer access daily challenge, though I can see the leaderboard. I still cannot access daily challenge after the update. I could access in May 2024, corresponding to my post www.gog.com/forum/dead_cells/how_to_daily_challenge_on_linux_by_running_gog_galaxy_client_via_wine

Judging by that the leaderboard is changing, daily challenge is at least accessible for some people. It is probable that those players are on Steam.

I am not a regular player anymore, but I've seen information about the game being dead and no longer in active development of new content (Notice the gap in deadcells.com/patchnotes on "The End is Near" update, 2023-10-02 is the last time updated before almost a year later Motion Twin / Evil Empire pushed the update from beta branch). That being said, that the update was pushed is still a good sign, and the game might still be supported (e.g. daily challenge issue on GOG). Good luck!

I hadn't thought about that.
Thank you for testing on an older version.

Trying to submit a request through the GOG Support system led me to this : https://support.gog.com/hc/en-us/articles/360008695033-Failed-There-is-a-problem-connecting-to-the-server-while-trying-to-play-Daily-Challenges?input_string=daily+challenge+inaccessible&product=gog

No date on the page however so it could have been submitted 5 years ago for all I know

I have the same problem. The game states that my internet connection has failed, even though the leaderboard updates. This has been happening since the last update.

I'm having the same problem and would like to at least unlock the Daily Challenge blueprints. Can't seem to find an answer anywhere

sebadorn.de/2021/06/28/dead-cells-unlocking-the-daily-challenge-blueprints-in-the-bugged-linux-gog-version mentions how to hack the game to unlock Daily Challenge blueprints on Linux. You may adapt it to your operating system.

Thanks for the tip