So I did load your save game and saw a worker next to the core.
But he just went idling away and no issue appeared, so I loaded it again twice with same result.
So all I can guess what ever issue you had there we did fix meanwhile either in one of the recent hotfixes or internally which will be then fixed with next patch.

I can not reproduce any real issue here, yes the door has a threat value and I see a corner case here.
So what they do is going to the tile, starting to claim and then get scared and flee.
They do this multiple times but finally manage to to claim the tile.
So I can not reproduce a "fighting glitch" and for me they show either claim or flee activity.

Improvement ticket created.

I am glad you got it sorted for you and I agree something like a clear warning when memory gets low would be useful.
However most of the time we are working on a much higher layer of abstraction and keep the memory management to the game engine (Unity).
And there must be surely ways to figure the current memory load, but we can only do this if it works for all supported platforms: Win32/Win64, OSX64 and Linux64 and this is where things can get fiddly and it might be that we finally need to implement it in multiple ways, one per platform.
However I will raise a low priority improvement ticket to investigate into such feature in future.

Cheers and thanks for letting us know.