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when u wipe servers its completely a new game right? All progression is lost?

@xXWoLfGaNgXx, yes. So PvP players have equal chances to succeed.
Next official PvP servers wipe is scheduled on Feb 14.

why did my basement suddenly disappear itself?
i really could not understand why
it is all gone
what the hell has happened?

@empire55508963, are you certain you're joining the same server you've played? Is your character with its progress there?
Most likely this is due to the land claim decay which is a necessity to prevent the world from cluttering the world with the abandoned bases. Its duration depends on the land claim tier and actual server you're playing on. You can find the information about the decay duration in the land claim window, "Decay info" tab: https://atomictorch.com/Files/Images/CryoFall_A23_LandClaimDecay_T3_PvE.jpg

The higher tier of a land claim, the longer the base will last if abandoned. In the case of the official PvE servers, Tier 5 land claim will last over two weeks, but Tier 1 only a few days (T3—well over a week[atomictorch.com], and it's achievable within 6-12 hours of the gameplay by the most players). If there are multiple land claims composing a base, the game will use the decay time from the highest tier. Everything is explained in the "Decay info" in the land claim menu to manage the expectations.

Regards!