I don't speak English well, so I used Google Translate.
When the 3rd assembly machine is destroyed in mission 4, the following error is displayed while normal dialogue is output, and the game crashes.

Error while running event level::on_tick (ID 0)
Must provide either a 'position' or 'target'
stack traceback:
[C]: in function 'set_controller'
...Data/Roaming/Factorio/temp/currently-playing/control.lua:447: in function 'init'
core/lualib/story.lua:56: in function 'story_update'
...Data/Roaming/Factorio/temp/currently-playing/control.lua:990: in function <...Data/Roaming/Factorio/temp/currently-playing/control.lua:987>

The scenario you made is really great. Thank you.

Hi, thank you for report.

I tryed to replikate the problem but I didn't find any issue. May I ask what exactly you did before, when you destroyed third assembly machine?

P.S.
It looks it just failed a cinematic scene, try to load few minutes earlier (autosave) and again destroy the assembly machine.

I maybe found the problem, but I'm not sure if this is the case.

Did you went to the fortified "secret" base, where are centrifuges before destroying assembly machines?

[Google translate] (sorry :/)

Thanks for your reply. I knew there was a huge enemy base with a centrifuge, but I didn't attack it.

Tried to play again with autosave game or new game, but always got the same error.

Regardless of the location, after destroying the last (3rd) pirate assembly machine, a crash occurred at the end of the dialogue event.

The action before destroying the last(3rd) assembly machine was to explore all the chests on the map and obtain the items.

The huge base with the centrifuge to the northwest only confirmed its location.

I'll today release a new version of the mod. Or you can try older version (version 1.0.5 is 100% ok) . Also I recoment to disable other mods which changing/removing vanila game entities.

Thanks to your advice, the problem was solved.

As you advised, I disabled all the modes and proceeded the scenario, and there was no crash.

I checked the modes I used one by one, I found that there was a collision with 'bottleneck'.

The reason was that the mode used in the previous mission was used as it was.

Thank you for answering quickly. :)

You're welcome. I will also put "bottleneck" mod to the black-list in description of my mod. :-)