NullReferenceException while joining without downloading the map

[ChongChengAC]

When i click "Open" without installing the map, SP crashed.

Crash log:

OpenRA engine version d44dccb41a05acce10a047c616fe03ccd7857e19
OpenRA Language: en
Shattered Paradise mod version playtest-20240921
Date: 2024-10-20 06:44:05Z
Operating System: Windows (X64, Microsoft Windows NT 10.0.19045.0)
Runtime Version: .NET CLR 6.0.33
Installed Language: zh (Installed) zh (Current) zh (Current UI)
Exception of type `System.NullReferenceException`: Object reference not set to an instance of an object.
   at OpenRA.Mods.Common.Widgets.Logic.LobbyUtils.ShowSlotDropDown(DropDownButtonWidget dropdown, Slot slot, Client client, OrderManager orderManager, MapPreview map, ModData modData) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyUtils.cs:line 75
   at OpenRA.Mods.Common.Widgets.Logic.LobbyUtils.<>c__DisplayClass26_0.<SetupEditableSlotWidget>b__4(MouseInput _) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyUtils.cs:line 457
   at OpenRA.Mods.Common.Widgets.ButtonWidget.HandleMouseInput(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Mods.Common/Widgets/ButtonWidget.cs:line 208
   at OpenRA.Widgets.Widget.HandleMouseInputOuter(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Widgets/Widget.cs:line 446
   at OpenRA.Widgets.Widget.HandleMouseInputOuter(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Widgets/Widget.cs:line 437
   at OpenRA.Widgets.Widget.HandleMouseInputOuter(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Widgets/Widget.cs:line 437
   at OpenRA.Widgets.Widget.HandleMouseInputOuter(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Widgets/Widget.cs:line 437
   at OpenRA.Widgets.Widget.HandleMouseInputOuter(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Widgets/Widget.cs:line 437
   at OpenRA.Widgets.Widget.HandleMouseInputOuter(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Widgets/Widget.cs:line 437
   at OpenRA.Widgets.Widget.HandleMouseInputOuter(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Widgets/Widget.cs:line 437
   at OpenRA.Widgets.Ui.HandleInput(MouseInput mi) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Widgets/Widget.cs:line 101
   at OpenRA.DefaultInputHandler.<>c__DisplayClass5_0.<OnMouseInput>b__0() in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Input/InputHandler.cs:line 50
   at OpenRA.Sync.RunUnsynced[T](Boolean checkSyncHash, World world, Func`1 fn) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Sync.cs:line 203
   at OpenRA.DefaultInputHandler.OnMouseInput(MouseInput input) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Input/InputHandler.cs:line 51
   at OpenRA.Platforms.Default.Sdl2Input.PumpInput(Sdl2PlatformWindow device, IInputHandler inputHandler, Nullable`1 lockedMousePosition) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Platforms.Default/Sdl2Input.cs:line 140
   at OpenRA.Platforms.Default.Sdl2PlatformWindow.PumpInput(IInputHandler inputHandler) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Platforms.Default/Sdl2PlatformWindow.cs:line 497
   at OpenRA.Renderer.EndFrame(IInputHandler inputHandler) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Renderer.cs:line 333
   at OpenRA.Game.RenderTick() in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Game.cs:line 748
   at OpenRA.Game.Loop() in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Game.cs:line 856
   at OpenRA.Game.Run() in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Game.cs:line 888
   at OpenRA.Game.InitializeAndRun(String[] args) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.Game/Game.cs:line 313
   at OpenRA.WindowsLauncher.WindowsLauncher.RunGame(String[] args) in /home/runner/work/Shattered-Paradise-SDK/Shattered-Paradise-SDK/engine/OpenRA.WindowsLauncher/Program.cs:line 71