[BUG] v2.2 stable: Incorrect region file header causes chunk reset/corruption when rejoining

[dgolveira]

[BUG] v2.2 stable: Incorrect region file header causes chunk reset/corruption when rejoining

Description

After updating to the newly public v2.2 (Docker image delivering VERSION=public), the server begins throwing Incorrect region file header errors that reset the chunk where my base is when I rejoin.

Initially, the server would not start on v2.2. I was able to start it by restarting the container, switching START_MODE from 3 to 1, and restoring the /save_game/Region folder from backup. The server then comes up and is playable.

However, when I rejoin, I remain in the same chunk, but many structures appear half-built. It looks like my base straddles a chunk border, and part of it is reset when the error occurs.

Logs

2025-08-08T15:28:24 37662.015 ERR ERROR: System.Exception: Incorrect region file header! /home/sdtdserver/.local/share/7DaysToDie/Saves/GalhofaWorld/save_game/Region/r.-2.-8.7rg
  at RegionFileSectorBased.Get (System.String dir, System.Int32 rX, System.Int32 rZ, System.String ext) [0x00061] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileAccessSectorBased.OpenRegionFile (System.String _dir, System.Int32 _regionX, System.Int32 _regionZ, System.String _ext) [0x00000] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileAccessMultipleChunks.GetRFC (System.Int32 _regionX, System.Int32 _regionZ, System.String _dir, System.String _ext) [0x00067] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileAccessMultipleChunks.Write (System.String _dir, System.Int32 _chunkX, System.Int32 _chunkZ, System.String _ext, System.Byte[] _buf, System.Int32 _bufLength) [0x0000c] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at ChunkMemoryStreamWriter.Close () [0x0002a] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileChunkWriter.WriteStreamCompressed (System.String dir, System.Int32 chunkX, System.Int32 chunkZ, System.String ext, System.IO.MemoryStream memoryStream) [0x00077] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileChunkSnapshot.Write (RegionFileChunkWriter writer, System.String dir, System.Int32 chunkX, System.Int32 chunkZ) [0x00008] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at ChunkSnapshotUtil.WriteSnapshot (IRegionFileChunkSnapshot snapshot, System.String dir, System.Int32 chunkX, System.Int32 chunkZ) [0x00000] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileManager.DoSaveChunks () [0x00244] in <b84f98912e6941559bfc9ef2eadfd3ba>:0

2025-08-08T15:28:26 37664.015 ERR ERROR: System.Exception: Incorrect region file header! /home/sdtdserver/.local/share/7DaysToDie/Saves/GalhofaWorld/save_game/Region/r.-2.-8.7rg
  at RegionFileSectorBased.Get (System.String dir, System.Int32 rX, System.Int32 rZ, System.String ext) [0x00061] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileAccessSectorBased.OpenRegionFile (System.String _dir, System.Int32 _regionX, System.Int32 _regionZ, System.String _ext) [0x00000] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileAccessMultipleChunks.GetRFC (System.Int32 _regionX, System.Int32 _regionZ, System.String _dir, System.String _ext) [0x00067] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileAccessMultipleChunks.Write (System.String _dir, System.Int32 _chunkX, System.Int32 _chunkZ, System.String _ext, System.Byte[] _buf, System.Int32 _bufLength) [0x0000c] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at ChunkMemoryStreamWriter.Close () [0x0002a] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileChunkWriter.WriteStreamCompressed (System.String dir, System.Int32 chunkX, System.Int32 chunkZ, System.String ext, System.IO.MemoryStream memoryStream) [0x00077] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileChunkSnapshot.Write (RegionFileChunkWriter writer, System.String dir, System.Int32 chunkX, System.Int32 chunkZ) [0x00008] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at ChunkSnapshotUtil.WriteSnapshot (IRegionFileChunkSnapshot snapshot, System.String dir, System.Int32 chunkX, System.Int32 chunkZ) [0x00000] in <b84f98912e6941559bfc9ef2eadfd3ba>:0
  at RegionFileManager.DoSaveChunks () [0x00244] in <b84f98912e6941559bfc9ef2eadfd3ba>:0

Steps to Reproduce

1. Pull and run the Docker image that serves v2.2 (e.g., image: vinanrra/7dtd-server with VERSION=public).
2. Start the server with an existing world/save.
3. In an area where the base likely spans a chunk boundary, log out and then rejoin (or wait for an autosave, then rejoin).
4. Observe the log error and that parts of the base are reset, as if one side of the boundary rolled back.

Expected behavior

No region header errors; chunks remain intact and persistent after rejoin.

Actual behavior

On rejoin (from a different chunk), the server logs Incorrect region file header and resets the affected chunk.

Workarounds Tried

• Restarting the container and changing START_MODE from 3 to 1.
• Restoring /save_game/Region from a backup created by the service.

These steps allow the server to boot, but the issue reappears later and leads to chunk reset upon rejoin.

Environment

• Image: vinanrra/7dtd-server (public → v2.2)
• Orchestration: Docker / docker-compose
• Networking: external Docker network games; an nginx at the edge performs TCP stream reverse proxy to this container because multiple game servers run on the same host.
• Save path example: /home/sdtdserver/.local/share/7DaysToDie/Saves/GalhofaWorld/save_game/Region/
• Mods: none enabled (unless image defaults apply)

docker-compose (for reference)

services:
  7DaysToDie:
    image: vinanrra/7dtd-server
    hostname: 7dtd
    container_name: 7dtd
    restart: unless-stopped          # INFO - NEVER USE WITH START_MODE=4 or START_MODE=0
    environment:
      - START_MODE=1                 # Change between START MODES
      - VERSION=public               # Change between 7 days to die versions
      - PUID=1000                    # Remember to use same as your user
      - PGID=1000                    # Remember to use same as your user
      - TimeZone=America/Sao_Paulo   # Optional - Change Timezone
      - TEST_ALERT=NO                # Optional - Send a test alert
      - UPDATE_MODS=NO               # Optional - This will allow mods to be update on start, each mod also need to have XXXX_UPDATE=YES to update on start
      - MODS_URLS=""                 # Optional - Mods urls to install, must be ZIP or RAR.
      - ALLOC_FIXES=NO               # Optional - Install ALLOC FIXES
      - ALLOC_FIXES_UPDATE=NO        # Optional - Update Allocs Fixes before server start
      - UNDEAD_LEGACY=NO             # Optional - Install Undead Legacy mod, if DARKNESS_FALLS it's enable will not install anything
      - UNDEAD_LEGACY_VERSION=stable # Optional - Undead Legacy version
      - UNDEAD_LEGACY_UPDATE=NO      # Optional - Update Undead Legacy mod before server start
      - DARKNESS_FALLS=NO            # Optional - Install Darkness Falls mod, if UNDEAD_LEGACY it's enable will not install anything
      - DARKNESS_FALLS_UPDATE=NO     # Optional - Update Darkness Falls mod before server start
      - DARKNESS_FALLS_URL=False     # Optional - Install the provided Darkness Falls url
      - CPM=NO                       # Optional - CSMM Patron's Mod (CPM)
      - CPM_UPDATE=NO                # Optional - Update CPM before server start
      - BEPINEX=NO                   # Optional - BepInEx
      - BEPINEX_UPDATE=NO            # Optional - Update BepInEx before server start
      - BACKUP=YES                   # Optional - Backup server
      - BACKUP_HOUR=5                # Optional - Backup hour 0-23
      - BACKUP_MAX=5                 # Optional - Max backups to keep
      - MONITOR=NO                   # Optional - Keeps server up if crash
    volumes:
      - ./Saves:/home/sdtdserver/.local/share/7DaysToDie/           # 7 Days To Die world saves
      - ./LGSM-Config:/home/sdtdserver/lgsm/config-lgsm/sdtdserver  # LGSM config folder
      - ./ServerFiles:/home/sdtdserver/serverfiles/                 # Optional - serverfiles folder
      - ./log:/home/sdtdserver/log/                                 # Optional - Logs folder
      - ./backups:/home/sdtdserver/lgsm/backup/                     # Optional - If BACKUP=NO, backups folder
    ports:
      - 26900:26900/tcp # Default game ports
      - 26900:26900/udp # Default game ports
      - 26901:26901/udp # Default game ports
      - 26902:26902/udp # Default game ports
    networks:
      - games
networks:
  games:
    external: true

Additional context

• I am not moved to another chunk when rejoining; I stay in the same chunk, but the base appears split across a boundary and loads partially reset.
• This started after v2.2 became public. I did not see this issue before.
• Happy to share a redacted save/region file for reproduction if helpful.

Questions

• Is there any migration or validation step required for region files in v2.2?
• Any known incompatibility/change in the region/chunk format between versions that could explain this?
• Would you like me to test a specific image tag or branch?