[NullReferenceException during blood moon]

Just an addition: There are more bugs around the electric fences:

 

1. As long as the wires are correctly managed by the game engine, the wires are "hanging through" proportionally to their deterioration. They get straitened as soon as the corresponding "receiving" fence posts gets repaired. This tends to be erroneous at nearly the same rate as the previously describes bugs. This bug is as well preventable to some degree by exit/reload with the player standing at the location of the fences.

2. The wires tend to get wrongly connected to the fence posts when you leave the location far enough and then return (as with all the other three bugs describes previously). While normally, the wire should run from TOP to TOP of the fence posts, the wire often runs from top to bottom or from bottom to bottom (thus criss cross or even sunken into the floor, thus becoming useless). As with all the other versions of bugs around electric fences, these bugs may be prevented by exit/reload with the player standing at the location of the fences.
 

[NullReferenceException during blood moon]

This is perfectly reliable to reproduce. I tend to play on max difficulty settings and because of that with a multitude of fences. With about 60 fences in place, those bugs would make the game unplayable.

But there is a method of countering those errors: As long as the game gets reloaded (exit -> continue) immediately before the horde night at the very place of the horde night, mostly (still not always) those errors are gone.

As Oxipe wrote, the error messages are NOT connected to the horde night, but to entities running through fences - as soon as those fences EXCEED A CERTAIN NUMBER. I'm still not certain about the exact limit, but having around 20 or more fences constitutes a near guarantee to get them. BUT: Exit/Reload while having the player standing at the location of the fences prevents them - mostly.

Furthermore, this bug MAY be correlated to the bug where fence wires get redirected into infinity.

For those not already knowing said bug: the wire between two fence posts can become redirected from one of the posts to a point in infinite distance. These wires have hitboxes and thus deliver shocks - up to infinite distance (well: at least up to the end of the map). These bugs also go away if you exit/reload the game while standing beside the affected fence posts.

IF you see a wire going in this way to infinity, you can be sure to get null reference exceptions as well. Not necessarily for the SAME wires, but you get them.

[Explosions can damage non-exposed blocks]

Explosions, if they are defined with explosion radius bigger that the distance to the wall in question, usually damage blocks in the second raw. The damage is far less than that for the first raw, but not null.

 

I have the impression that the filling of the volume, expressed in the block definitions as "opacity", has no influence on that ration of damage (first to second raw). Maybe the Funpimps could make this dependent on the opacity?

[Enemy Animals can climb ladders despite "CanClimbLadders"="false"]

Could you please post a link to the previous bug report?

[Vertical block stability not restored when replacing blocks or placing blocks under others]

In case this helps get the idea where and how exactly the bug is happening:

 

The blocks above the stability-restoring-block are handled LIKE they were hanging sideways. I am absolutely certain that you HAVE the correct code lines somewhere in you code, but make some mistake at a logical switch where the decision is made how to handle the stability propagation.