I've encountered a server-crash bug on a multiplayer server I run, that happens when I try to remove an Exclusion from Outpost Builder.

  89.339 Error MainLoop.cpp:1283: Exception at tick 100117942: The mod TSM Outpost Builder Addon (1.1.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event TSM-outpost-builder::on_gui_click (ID 1)
__TSM-outpost-builder__/control.lua:697: attempt to index field 'exclusion_frame' (a nil value)
stack traceback:
    __TSM-outpost-builder__/control.lua:697: in function <__TSM-outpost-builder__/control.lua:607>
  89.339 Error ServerMultiplayerManager.cpp:91: MultiplayerManager failed: "The mod TSM Outpost Builder Addon (1.1.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event TSM-outpost-builder::on_gui_click (ID 1)
__TSM-outpost-builder__/control.lua:697: attempt to index field 'exclusion_frame' (a nil value)
stack traceback:
    __TSM-outpost-builder__/control.lua:697: in function <__TSM-outpost-builder__/control.lua:607>"
  89.339 Info ServerMultiplayerManager.cpp:797: updateTick(100117942) changing state from(InGame) to(Failed)
  89.355 Quitting: multiplayer error.
  90.670 Info ServerMultiplayerManager.cpp:140: Quitting multiplayer connection.
  90.670 Info ServerMultiplayerManager.cpp:797: updateTick(4294967295) changing state from(Failed) to(Closed)
  90.671 Info HttpSharedState.cpp:54: Downloading https://multiplayer.factorio.com/remove-game/11154829
  91.017 Info UDPSocket.cpp:218: Closing socket
  91.017 Info UDPSocket.cpp:248: Socket closed
  91.018 Goodbye

I went ahead and dug into this to find and fix the bug. It's fixed in my Redux version of the mod, but I'm happy to share the fix with LordKTor if they want it. (I plan to work on extending my version to do some other stuff too, but that's still down the road.)

https://mods.factorio.com/mod/tsm-outpost-builder-redux