I have started a map in 16.15 and upgraded into most versions while playing.
For some reason I have found a gun turret that I cannot remove.
In the image below I have tried right clicking it to remove and I just get "This Cannot Be Mined":
20180325121720_1.jpg
The deconstruction planner with no ...

Having the same issue, at first I thought it was due to placing a ghost of red belt so I got a save just before I did that, now however it crashes without me doing anything.
Attached save (started in [0.16.16]), factorio-dump-current.dmp and factorio-current.log

factorio-dump-current.dmp ...

after a bit more investigation this may end up in the 1/0 Magic sub section 8-), its just one of the oddities of the fluid mechanics.

I have not seen it move a value >= 1 into the other tank.
I have noticed that if I move the oil train out of the station in the previous save, then the water pump ...

There are no mods involved in this issue.

Bit of random preamble :
I was looking at reddit and saw an issue that someone was having trying to sort liquids:
https://www.reddit.com/r/factorio/comments/7n5ptd/00_liquidsorting_liquids/
so I figured I would see if I could find a solution to it, however ...

No-Mods enabled.

Since the update to 0.16.7 the fluid wagon now has 'Unknown Key:"fluid-contents"' under the 'Storage Limit' and above 'Temperature'

This appears to happen regardless of contents (water/crude oil/heavy oil etc.)

Attached an image.