Not sure if it's a subworldlibrary problem, a thestarsabove problem or a tmodloader problem.
Reproducible even with only the host player online.
[05:11:46.063] [Main Thread/INFO] [tML]: Starting tModLoader server 1.4.4.9+2023.10.3.0|2023.10|stable|Stable|23aa262bde1ae5440cf2b05b2f676feb787cdc95|5250055878079335727 built 2023/12/1 8:06
[05:11:46.073] [Main Thread/INFO] [tML]: Log date: 2024/1/1
[05:11:46.074] [Main Thread/INFO] [tML]: Running on Windows (v10.0.22621.0) X64 NetCore 6.0.14
[05:11:46.074] [Main Thread/INFO] [tML]: FrameworkDescription: .NET 6.0.14
[05:11:46.074] [Main Thread/INFO] [tML]: Executable: C:\Program Files (x86)\Steam\steamapps\common\tModLoader\tModLoader.dll
[05:11:46.074] [Main Thread/INFO] [tML]: Working Directory: C:\Program Files (x86)\Steam\steamapps\common\tModLoader
[05:11:46.074] [Main Thread/INFO] [tML]: Launch Parameters: -server -autoshutdown -password 1111 -lang 1 -world d:\Documents\My Games\Terraria\tModLoader\Worlds\starAboveWorld.wld -worldrollbackstokeep 2 -modpath d:\Documents\My Games\Terraria\tModLoader\Mods -steam -localsteamid [redacted] -lobby friends
[05:11:46.078] [Main Thread/INFO] [tML]: Parsed Launch Parameters: -server -autoshutdown -password 1111 -lang 1 -world d:\Documents\My Games\Terraria\tModLoader\Worlds\starAboveWorld.wld -worldrollbackstokeep 2 -modpath d:\Documents\My Games\Terraria\tModLoader\Mods -steam -localsteamid [redacted] -lobby friends
[05:11:46.796] [Main Thread/INFO] [tML]: Saves Are Located At: d:\Documents\My Games\Terraria\tModLoader
[05:11:47.247] [Main Thread/INFO] [tML]: Distribution Platform: Steam. Detection method: -steam launch parameter
[05:11:47.688] [Main Thread/INFO] [tML]: Attempt to Port from "C:\Program Files (x86)\Steam\userdata\[redacted]\105600\remote\tModLoader" to "C:\Program Files (x86)\Steam\userdata\[redacted]\105600\remote\tModLoader-1.4.3" aborted, "2023.10.3.0" is a newer version.
[05:11:47.703] [Main Thread/INFO] [Terraria]: Steam Cloud Quota: 840.2 MB available
[05:11:47.703] [Main Thread/INFO] [tML]: Steam beta branch: None
[05:11:47.704] [Main Thread/INFO] [tML]: SteamBackend: Running standard Steam Desktop Client API
[05:11:47.706] [Main Thread/INFO] [tML]: Current 1281930 Workshop Folder Directory: C:\Program Files (x86)\Steam\steamapps\common\tModLoader\..\..\workshop
[05:11:49.481] [Main Thread/DEBUG] [tML]: Network compatibility version is 2023.10.3
[05:11:52.174] [Main Thread/INFO] [tML]: Finding Mods...
[05:11:52.203] [Main Thread/INFO] [tML]: Sandboxing: SubworldLibrary (Subworld Library) v2.2.2
[05:11:52.264] [Main Thread/INFO] [tML]: Sandboxing: StarsAbove ([c/EC1B9D:The Stars Above]) v2.0.2.1
[05:11:52.446] [Main Thread/INFO] [tML]: Constructing Mods...
[05:11:52.641] [Main Thread/INFO] [tML]: Adding Content: ModLoader (tModLoader) v2023.10.3.0
[05:11:52.758] [Main Thread/INFO] [tML]: Adding Content: SubworldLibrary (Subworld Library) v2.2.2
[05:11:52.909] [Main Thread/DEBUG] [tML]: ILHook Terraria.Main::DedServ_PostModLoad(out bool) added by SubworldLibrary
[05:11:52.922] [Main Thread/DEBUG] [tML]: ILHook Terraria.NetMessage::CheckBytes(int) added by SubworldLibrary
[05:11:52.925] [Main Thread/DEBUG] [tML]: ILHook Terraria.Net.Sockets.SocialSocket::Terraria.Net.Sockets.ISocket.AsyncSend(Byte[], int, int, SocketSendCallback, object) added by SubworldLibrary
[05:11:52.929] [Main Thread/DEBUG] [tML]: ILHook Terraria.Net.Sockets.TcpSocket::Terraria.Net.Sockets.ISocket.AsyncSend(Byte[], int, int, SocketSendCallback, object) added by SubworldLibrary
[05:11:52.935] [Main Thread/DEBUG] [tML]: ILHook Terraria.Netplay::UpdateConnectedClients() added by SubworldLibrary
[05:11:52.939] [Main Thread/DEBUG] [tML]: ILHook Terraria.Main::EraseWorld(int) added by SubworldLibrary
[05:11:52.959] [Main Thread/DEBUG] [tML]: ILHook Terraria.Main::DoUpdateInWorld(Stopwatch) added by SubworldLibrary
[05:11:52.966] [Main Thread/DEBUG] [tML]: ILHook Terraria.WorldGen::UpdateWorld() added by SubworldLibrary
[05:11:53.272] [Main Thread/DEBUG] [tML]: ILHook Terraria.Player::Update(int) added by SubworldLibrary
[05:11:53.276] [Main Thread/DEBUG] [tML]: ILHook Terraria.NPC::UpdateNPC_UpdateGravity() added by SubworldLibrary
[05:11:53.310] [Main Thread/DEBUG] [tML]: ILHook Terraria.Liquid::Update() added by SubworldLibrary
[05:11:53.314] [Main Thread/DEBUG] [tML]: ILHook Terraria.Player::SavePlayer(PlayerFileData, bool) added by SubworldLibrary
[05:11:53.317] [Main Thread/DEBUG] [tML]: ILHook Terraria.IO.WorldFile::SaveWorld(bool, bool) added by SubworldLibrary
[05:11:53.376] [Main Thread/INFO] [tML]: Adding Content: StarsAbove ([c/EC1B9D:The Stars Above]) v2.0.2.1
[05:11:54.622] [Main Thread/DEBUG] [tML]: Hook Terraria.Graphics.Light.TileLightScanner::GetTileLight(int, int, out Vector3) added by StarsAbove
[05:11:54.632] [Main Thread/DEBUG] [tML]: Hook Terraria.Graphics.Light.TileLightScanner::GetTileLight(int, int, out Vector3) added by StarsAbove
[05:11:54.642] [Main Thread/WARN] [tML]: StarsAbove.Systems.Items.ItemMemorySystem has reference fields (EquippedMemories, globalItem) that may not be safe to share between clones.
For deep-cloning, add a custom Clone override and make proper copies of these fields. If shallow (memberwise) cloning is acceptable, mark the fields with [CloneByReference] or properties with [field: CloneByReference]
[05:11:54.687] [Main Thread/DEBUG] [tML]: ILHook Terraria.ModLoader.UI.UIModItem::OnInitialize() added by StarsAbove
[05:11:54.689] [Main Thread/INFO] [StarsAbove]: 'I've always wanted to write text in crash logs!' -A
[05:11:54.690] [Main Thread/INFO] [StarsAbove]: 'Eh? Doesn't that make you look like you caused it..?' -E
[05:11:54.804] [Main Thread/INFO] [tML]: Resizing...
[05:11:55.222] [Main Thread/INFO] [tML]: Configuring Content: ModLoader (tModLoader) v2023.10.3.0
[05:11:55.297] [Main Thread/INFO] [tML]: Configuring Content: SubworldLibrary (Subworld Library) v2.2.2
[05:11:55.353] [Main Thread/INFO] [tML]: Configuring Content: StarsAbove ([c/EC1B9D:The Stars Above]) v2.0.2.1
[05:11:55.915] [Main Thread/INFO] [tML]: Finalizing Content: ModLoader (tModLoader) v2023.10.3.0
[05:11:55.990] [Main Thread/INFO] [tML]: Finalizing Content: SubworldLibrary (Subworld Library) v2.2.2
[05:11:56.064] [Main Thread/INFO] [tML]: Finalizing Content: StarsAbove ([c/EC1B9D:The Stars Above]) v2.0.2.1
[05:11:56.157] [Main Thread/INFO] [tML]: RAM: tModLoader usage: 370.4 MB, All processes usage: 15.8 GB, Available: 4.1 GB, Total Installed: 20.0 GB
[05:11:56.473] [Main Thread/DEBUG] [tML]: GlobalItem registration stats. Count: 3, Slots per Entity: 3
Instanced: 3, Conditional with slot: 0, Conditional by type: 0, Applies to single type: 0
List Permutations: 1, Est Memory Consumption: 16 bytes
[05:11:56.554] [Main Thread/DEBUG] [tML]: GlobalNPC registration stats. Count: 15, Slots per Entity: 12
Instanced: 12, Conditional with slot: 0, Conditional by type: 0, Applies to single type: 0
List Permutations: 1, Est Memory Consumption: 16 bytes
[05:11:56.580] [Main Thread/DEBUG] [tML]: GlobalProjectile registration stats. Count: 1, Slots per Entity: 0
Instanced: 0, Conditional with slot: 0, Conditional by type: 0, Applies to single type: 0
List Permutations: 1, Est Memory Consumption: 16 bytes
[05:11:56.710] [Main Thread/INFO] [tML]: Adding Recipes...
[05:11:57.765] [.NET ThreadPool Worker/INFO] [Terraria]: Loading World: starAboveWorld, IsCloud=False, Width: 6400, Height: 1800, Evil: 1, GameMode: 2
[05:11:57.824] [.NET ThreadPool Worker/INFO] [StatusText]: Loading world data
[05:11:59.054] [.NET ThreadPool Worker/INFO] [StatusText]: Settling liquids
[05:11:59.603] [Main Thread/INFO] [Terraria]: Running one update...
[05:11:59.604] [Main Thread/INFO] [tML]: Server starting with AllowVanillaClients set to False
[05:12:02.126] [15/DEBUG] [tML]: SSDP search line separator: CRLF
[05:12:02.190] [Main Thread/INFO] [Terraria]: Listening on port 7777
[05:12:02.468] [TCP Listen Thread/INFO] [Terraria]: 127.0.0.1:53282 is connecting...
[05:12:11.654] [5/INFO] [tML]: Currently Hosting LobbyID: 0
[05:12:11.718] [Main Thread/DEBUG] [tML]: Sending Server Config StarsAbove:StarsAboveServersideConfig {}
[05:12:12.328] [Main Thread/INFO] [Terraria]: stargazingCB has joined.
[05:12:54.978] [Main Thread/DEBUG] [tML]: Process.Start (UseShellExecute = True): "C:\Program Files (x86)\Steam\steamapps\common\tModLoader\dotnet\6.0.14\dotnet.exe" tModLoader.dll -server -showserverconsole -world "d:\Documents\My Games\Terraria\tModLoader\Worlds\starAboveWorld.wld" -subworld "StarsAbove_Observatory"
[05:12:55.741] [Main Thread/INFO] [tML]: Starting tModLoader server 1.4.4.9+2023.10.3.0|2023.10|stable|Stable|23aa262bde1ae5440cf2b05b2f676feb787cdc95|5250055878079335727 built 2023/12/1 8:06
[05:12:55.750] [Main Thread/INFO] [tML]: Log date: 2024/1/1
[05:12:55.751] [Main Thread/INFO] [tML]: Running on Windows (v10.0.22621.0) X64 NetCore 6.0.14
[05:12:55.751] [Main Thread/INFO] [tML]: FrameworkDescription: .NET 6.0.14
[05:12:55.751] [Main Thread/INFO] [tML]: Executable: C:\Program Files (x86)\Steam\steamapps\common\tModLoader\tModLoader.dll
[05:12:55.751] [Main Thread/INFO] [tML]: Working Directory: C:\Program Files (x86)\Steam\steamapps\common\tModLoader
[05:12:55.752] [Main Thread/INFO] [tML]: Launch Parameters: -server -showserverconsole -world d:\Documents\My Games\Terraria\tModLoader\Worlds\starAboveWorld.wld -subworld StarsAbove_Observatory
[05:12:55.754] [Main Thread/INFO] [tML]: Parsed Launch Parameters: -server -showserverconsole -world d:\Documents\My Games\Terraria\tModLoader\Worlds\starAboveWorld.wld -subworld StarsAbove_Observatory
[05:12:56.365] [Main Thread/INFO] [tML]: Saves Are Located At: d:\Documents\My Games\Terraria\tModLoader
[05:12:56.851] [Main Thread/INFO] [tML]: Distribution Platform: Steam. Detection method: CWD is /steamapps/
[05:12:57.120] [Main Thread/INFO] [tML]: Current 1281930 Workshop Folder Directory: .\..\..\workshop
[05:12:58.890] [Main Thread/DEBUG] [tML]: Network compatibility version is 2023.10.3
[05:13:01.648] [Main Thread/INFO] [tML]: Finding Mods...
[05:13:01.678] [Main Thread/INFO] [tML]: Sandboxing: SubworldLibrary (Subworld Library) v2.2.2
[05:13:01.744] [Main Thread/INFO] [tML]: Sandboxing: StarsAbove ([c/EC1B9D:The Stars Above]) v2.0.2.1
[05:13:01.925] [Main Thread/INFO] [tML]: Constructing Mods...
[05:13:02.127] [Main Thread/INFO] [tML]: Adding Content: ModLoader (tModLoader) v2023.10.3.0
[05:13:02.242] [Main Thread/INFO] [tML]: Adding Content: SubworldLibrary (Subworld Library) v2.2.2
[05:13:02.405] [Main Thread/DEBUG] [tML]: ILHook Terraria.Main::DedServ_PostModLoad(out bool) added by SubworldLibrary
[05:13:02.413] [Main Thread/DEBUG] [tML]: ILHook Terraria.Main::EraseWorld(int) added by SubworldLibrary
[05:13:02.433] [Main Thread/DEBUG] [tML]: ILHook Terraria.Main::DoUpdateInWorld(Stopwatch) added by SubworldLibrary
[05:13:02.437] [Main Thread/DEBUG] [tML]: ILHook Terraria.WorldGen::UpdateWorld() added by SubworldLibrary
[05:13:02.755] [Main Thread/DEBUG] [tML]: ILHook Terraria.Player::Update(int) added by SubworldLibrary
[05:13:02.759] [Main Thread/DEBUG] [tML]: ILHook Terraria.NPC::UpdateNPC_UpdateGravity() added by SubworldLibrary
[05:13:02.793] [Main Thread/DEBUG] [tML]: ILHook Terraria.Liquid::Update() added by SubworldLibrary
[05:13:02.798] [Main Thread/DEBUG] [tML]: ILHook Terraria.Player::SavePlayer(PlayerFileData, bool) added by SubworldLibrary
[05:13:02.802] [Main Thread/DEBUG] [tML]: ILHook Terraria.IO.WorldFile::SaveWorld(bool, bool) added by SubworldLibrary
[05:13:02.853] [Main Thread/INFO] [tML]: Adding Content: StarsAbove ([c/EC1B9D:The Stars Above]) v2.0.2.1
[05:13:04.126] [Main Thread/DEBUG] [tML]: Hook Terraria.Graphics.Light.TileLightScanner::GetTileLight(int, int, out Vector3) added by StarsAbove
[05:13:04.137] [Main Thread/DEBUG] [tML]: Hook Terraria.Graphics.Light.TileLightScanner::GetTileLight(int, int, out Vector3) added by StarsAbove
[05:13:04.147] [Main Thread/WARN] [tML]: StarsAbove.Systems.Items.ItemMemorySystem has reference fields (EquippedMemories, globalItem) that may not be safe to share between clones.
For deep-cloning, add a custom Clone override and make proper copies of these fields. If shallow (memberwise) cloning is acceptable, mark the fields with [CloneByReference] or properties with [field: CloneByReference]
[05:13:04.196] [Main Thread/DEBUG] [tML]: ILHook Terraria.ModLoader.UI.UIModItem::OnInitialize() added by StarsAbove
[05:13:04.199] [Main Thread/INFO] [StarsAbove]: 'I've always wanted to write text in crash logs!' -A
[05:13:04.199] [Main Thread/INFO] [StarsAbove]: 'Eh? Doesn't that make you look like you caused it..?' -E
[05:13:04.315] [Main Thread/INFO] [tML]: Resizing...
[05:13:04.816] [Main Thread/INFO] [tML]: Configuring Content: ModLoader (tModLoader) v2023.10.3.0
[05:13:04.891] [Main Thread/INFO] [tML]: Configuring Content: SubworldLibrary (Subworld Library) v2.2.2
[05:13:04.945] [Main Thread/INFO] [tML]: Configuring Content: StarsAbove ([c/EC1B9D:The Stars Above]) v2.0.2.1
[05:13:05.555] [Main Thread/INFO] [tML]: Finalizing Content: ModLoader (tModLoader) v2023.10.3.0
[05:13:05.632] [Main Thread/INFO] [tML]: Finalizing Content: SubworldLibrary (Subworld Library) v2.2.2
[05:13:05.710] [Main Thread/INFO] [tML]: Finalizing Content: StarsAbove ([c/EC1B9D:The Stars Above]) v2.0.2.1
[05:13:05.803] [Main Thread/INFO] [tML]: RAM: tModLoader usage: 360.4 MB, All processes usage: 16.7 GB, Available: 3.3 GB, Total Installed: 20.0 GB
[05:13:06.118] [Main Thread/DEBUG] [tML]: GlobalItem registration stats. Count: 3, Slots per Entity: 3
Instanced: 3, Conditional with slot: 0, Conditional by type: 0, Applies to single type: 0
List Permutations: 1, Est Memory Consumption: 16 bytes
[05:13:06.202] [Main Thread/DEBUG] [tML]: GlobalNPC registration stats. Count: 15, Slots per Entity: 12
Instanced: 12, Conditional with slot: 0, Conditional by type: 0, Applies to single type: 0
List Permutations: 1, Est Memory Consumption: 16 bytes
[05:13:06.225] [Main Thread/DEBUG] [tML]: GlobalProjectile registration stats. Count: 1, Slots per Entity: 0
Instanced: 0, Conditional with slot: 0, Conditional by type: 0, Applies to single type: 0
List Permutations: 1, Est Memory Consumption: 16 bytes
[05:13:06.360] [Main Thread/INFO] [tML]: Adding Recipes...
[05:13:08.468] [Main Thread/DEBUG] [tML]: Sending Server Config StarsAbove:StarsAboveServersideConfig {}
[05:13:11.057] [14/DEBUG] [tML]: SSDP search line separator: CRLF
[05:13:11.660] [Main Thread/INFO] [Terraria]: stargazingCB has joined.
[05:13:21.702] [Main Thread/WARN] [tML]: Silently Caught Exception:
System.ObjectDisposedException: Cannot access a closed Stream.
at System.IO.MemoryStream.get_Position()
at Terraria.ModLoader.ModNet.HandleModPacket(BinaryReader reader, Int32 whoAmI, Int32 length) in tModLoader\Terraria\ModLoader\ModNet.cs:line 502
at Terraria.MessageBuffer.GetData(Int32 start, Int32 length, Int32& messageType) in tModLoader\Terraria\MessageBuffer.cs:line 3887
at Terraria.NetMessage.CheckBytes(Int32 bufferIndex) in tModLoader\Terraria\NetMessage.cs:line 2384
at Terraria.Netplay.UpdateServerInMainThread() in tModLoader\Terraria\Netplay.cs:line 59
at Terraria.Main.DoUpdate(GameTime& gameTime) in tModLoader\Terraria\Main.cs:line 14195
at Terraria.Main.Update(GameTime gameTime) in tModLoader\Terraria\Main.cs:line 14094
at DMD<System.Void Terraria.Main:DedServ_PostModLoad(System.Boolean&)>(Main this, Boolean& reloadMods)
at SyncProxy<System.Void Terraria.Main:DedServ_PostModLoad(System.Boolean&)>(Main , Boolean& )
at Terraria.Main.DedServ() in tModLoader\Terraria\Main.cs:line 4528
at Terraria.Program.RunGame() in tModLoader\Terraria\Program.cs:line 264
at Terraria.Program.LaunchGame_(Boolean isServer) in tModLoader\Terraria\Program.cs:line 240
at Terraria.Program.LaunchGame(String[] args, Boolean monoArgs) in tModLoader\Terraria\Program.cs:line 213
at Terraria.MonoLaunch.Main_End(String[] args) in tModLoader\Terraria\MonoLaunch.cs:line 78
at Terraria.MonoLaunch.<>c__DisplayClass1_0.<Main>b__1() in tModLoader\Terraria\MonoLaunch.cs:line 64
at System.Threading.Thread.StartCallback()