Hello, I have the same problem after yesterday's update the server disappeared, in the backup folder (C:\Users\XXX\AppData\LocalLow\IronGate\Valheim\worlds) there is no, moreover for 2 weeks I can no longer do cloud synchronization (only on the valheim). I am very disgusted!!

good, after having restarted the cloud even if this one tells me that it cannot synchronize my world reappeared on the other hand when I launch the last backup the world is empty, suddenly I launch the previous backup, 1 day before and I found them all, I hope this solution will help some, otherwise courage to you and have a nice day.

SAME! This just happened today. What changed?? My entire world is gone and I am very sad.

Were you running the dedicated server via Docker by chance?

Did you back up the start_server file before you updated? World is still probably there the file just gets overwritten by updated one