Ok, let's sort this a bit.
1. It's not "iCloud". That's an Apple product.
2. Of course you have Steam, as Valheim only exists on Steam so far.
3. The update didn't "move" things to the cloud, Steam was doing this the whole time. In the latest patch(es) IronGate fixed several problems specifically in regards to cloud saves (and introduced new issues with it).
4. Your problem is the Steam Cloud service, especially in conjunction with Valheim.

Here's how to hopefully get your stuff back:
1. Turn off Steam Cloud in the global Steam settings. It's absolutely useless and rather harmful to players with not so reliable internet connections.
2. You need to go here:
https://store.steampowered.com/account/remotestorage
... click on Valheim and look for your world by name. It doesn't matter if the world name is hidden in a long string of seemingly garbage. It's just important that you find it.
3. There should be two files you need to find.
a. One ends in .db and is the actual world.
b. One ends in .fwl and is needed as well.
You need to look at the dates in the column to the right which is the latest one. THAT one might be corrupt, so look for one a day earlier.
4. Download both .db and .fwl file. They need to have exactly matching names!
5. You DID turn off Steam Cloud in the global Steam settings, right? If not, do it.
6. Quit Steam completely.
7. You need to go here on your PC:
8. There should be two folders named "Characters" and "Worlds" listed there. Enter the "Worlds" folder.
9. The two downloaded files probably have some weird names like YOURWORLD_backup_20220719_123456.db. You need to rename them to just YOURWORLD.db and YOURWORLD.fwl respectively.
10. COPY these files into the "Worlds" folder at the location listed above. KEEP the originals in a safe place.
11. Start Steam. Start Valheim. Test.

If the world is back in working order, you are HIGHLY encouraged to start doing periodic backups of ALL your important data! Data corruption IS a thing! Computers CAN and WILL fail!

It is solely up to you to keep your stuff safe from loss. Nobody else can be blamed for this.

Just a friendly reminder. Please let me know if my directions helped.

Good Luck!

No idea. Nobody else has mentioned this problem and you give no useful info. It's like saying my car won't start, how do I fix it.

Originally posted by Tachyon:

No idea. Nobody else has mentioned this problem and you give no useful info. It's like saying my car won't start, how do I fix it.

He doesnt seem to legally own the game xD at least not on steam...

sorry i got 2 accounts and both of them have different save files but this one world server didnt save my proggress, maybe beuacse i clicked on quit instead of logout?? even though i saw on the top right notification saving world saved.

Originally posted by MeGa:

Originally posted by Tachyon:

No idea. Nobody else has mentioned this problem and you give no useful info. It's like saying my car won't start, how do I fix it.

He doesnt seem to legally own the game xD at least not on steam...

wait or do i have to play on the main account i bought it from? gg...

since the update to move to icloud, my game was lost, and it wont keep the game when i log in the next day. I have steam.