ok thanks i will try ;)

Are you playing on a dedicated server by any chance?

I did but it does not change anything unfortunately but thank you very much for your help I will see to start all over from the beginning

no i play solo i have not dedicated server

How are you disconnecting? Are you hitting ALT+F4? Is it crashing?

I've heard of an issue with losing activity but the person I know that experienced it was playing on a dedicated server. They had to perform manual saves through the console or wait until they were sure the server had performed the world save.

No I escape quit the game and I play solo

Well, the console save is an option to further check where things might be failing. I'm sure someone will correct this if it's wrong but I'm fairly sure you only need to:

1) Add to the launch options of the game.
2) When you want to quit hit F5 and type save, then hit enter.

What does "deco reco" mean?

Are you using mods?

Sorry disconnection, reconnection. No mod in my game

Originally posted by Audallys:

Sorry disconnection, reconnection. No mod in my game

So are you saying the game closed improperly due to a disconnect issue?

No, I disconnected for irl and when I returned to the game I had piles of soil in front of the door of my house while I had terraform before the disconnection. Sorry for my english

So I started terraforming again and it started again I disconnected and when I came back into play the piles of earth instead

Ah, understood, sorry about my confusion there.

Only thing I can think of is to make sure your save file location isn't set to read only.

Do you use steam cloud?

Yes for steam cloud

Start Steam but not Valheim. Find Valheim on the list of games installed and right-click on it. Select Properties on the resulting drop-down menu. When the window pops up, select
Verify game files. Let Steam do its thing. When it is finished, start the game, do some terraforming. The disconnect and reconnect and see if your terraforming is as you left it.

I am no programmer but it sounds like your game is not saving correctly. If that is due to a problem with the program files, verifying the game files or uninstalling, the reinstalling Valheim may take care of it. It could be a hardware problem where the disk drive has a defect also. That used to be a common problem years ago which led to to gnashing of teeth, rending of clothes, and uttering profane language.

Good luck!