This is a known issue with the walls the dev is aware of this and it has
already been reported to the developer Jordi by different people.

There is a thread for this bug located at
https://www.xsyon.com/project.php?issueid=2427

It was also reported by me at
https://www.xsyon.com/project.php?issueid=2541

Sadly it's been an issue for quite some time, first discovered it during one of my many rebuilds of "pets corner", I can't remember if it was a railing or a wall I removed from the 1st floor, but next thing I knew my original pair of coyotes were out and running about outside my tribe.

I believe the main issue is with walls, but I know gates can be affected by it too, dismantling anything that just happens to touch the ends of a wall will "break" that wall.

Now the big issue is that once a wall has become broken you have problems, as dismantling that wall will pass the issue onto the next one, there are only two ways to deal with it, patch it with other constructs, or dismantle everything and start over.

I patched my place in 904 because at the time the outside walls were 5 stories high and I didn't fancy tearing that down to the ground, so I used Corrigated walls on the outside to block anything from getting in or out through the broken walls.

My place over on War had to be torn down and rebuilt, as I didn't have the Corrigated wall BP back then to patch with.

I had to add walls against walls to stop the critters from getting in which really looks tacky but for now it will have to do. When I have more time I will probably tear down the entire wall and start over. Im glad to know others are having same issue. Maybe this will be fixed soon.

The developer is aware of this and is working on it I am sure.

it seems to have gotten worse because i watched a pet walk through over a sunken wall that was about 1 metre above the ground,
over a small ramp and then through 2 fortress gates that were closed.

And nothing was dismantled anywhere near, and those arch objects the pet walked through had been inplace for months.

It is being worked on ... The developer already knows about this bug there is already a thread for this
particular bug. Can some one please close off this thread since there is already a thread about
this bug please. https://www.xsyon.com/project.php?issueid=2427

Thank you,

Actually these are separate issues, the OP is talking about an issue where you have a wall that was working, but because you dismantled something touching it that wall no longer registers with the AI pathing.

The issue chojinuk is describing sounds similar to complaints I've seen recently in chat, players have logged on after a server reset to find some of their pets have gotten out.

DarkShado, the issue you have linked to sounds like the ages old AI pathing telling the mob that the walls are above/below where the mob is moving.
While we see a world that's all lumps and bumps, the AI sees a flat plane as does the pathing, one example of this in action is a critter going up a vertical cliff, as far as it's concerned it's only travelling a couple of meters horizontally, which is why it goes up that cliff like it's got a rocket up it's butt. Same thing if you terraform a dirt wall around your tribe and stick a wall on top, as far as the critters are concerned the dirt wall doesn't exist and the arch wall is a couple of meters above their head and not blocking them.

Yup, this is a known issue (as posted and linked to above).

There are several issues due to the original system relying on conditions that are no longer valid (single story construction only, walls only blocking path, different spacing and sizing of parts).

I'm reworking path-finding as a big part of the creature revisions I've been working on. The path-finding is complicated due to the very interesting constructions you players have made, but it's getting there!

Thanks!