Looks like the last update may have caused a problem with seeing active puzzles. Turns out that first update was not intended, and the second update undid the first update. Things should be working now, please let us know over in the feedback section if there are continued issues.
Thanks for your patience.
I'm not seeing any active puzzles (Unix/Main)
I am only seeing the Beginner Puzzles. (Windows/Main). Let's hope this issue can be fixed promptly.
The current puzzles can be found by selecting the "Show expired puzzles" checkbox.
Check the "Show Expired Puzzles" checkbox on the puzzles menu, then enter a current puzzle number - 1336, 1337, or 1338 – in the search box. This may help, at least on clients that have been running.
There was also an unannounced software update last night (US time). It's not clear what the update did. It may have had some effect on which puzzles are displayed.
The recent unannounced software update was a mistake and has been rolled back. If you are having problems restart foldit and take the update.