Walls stop supporting roofs

[Yawinsum]

I should preface this by saying that I have heavily modified the game.  That said, during play, my walls just stop supporting roofs.  I can start up a new colony and they work fine, but after a while they just seem to stop supporting any roofs.  If you look in the pictures below the first one shows that the room is  15 blocks wide, so that one collapse is expected.  But in the second picture, AFTER building a wall on the left side, there is a huge collapse which should not have happened.  Those walls are close enough that they should support any roof between them.  I could really use any help in sorting out this bug.  A list of all the mods I have installed are in the second Imgur album.

Ok, guess the forums don't like Imgur too much.  I'll just share a link to my album.
http://imgur.com/a/nqcop

Modlist
http://imgur.com/a/pCPOP

[BlackSmokeDMax]

Have you tried putting a door in that opening along the left side. If the corridor leads to an unroofed area without a door somewhere in between, that may be the problem.

[milon]

Can you reproduce this in a vanilla game? 

If yes, please describe the exact steps and include the log file.

If not, it's mods related and will be moved into Mods Bugs.  We'll still need the steps to reproduce, including your full mod order (or a reproducer set).

[Yawinsum]

Have you tried putting a door in that opening along the left side. If the corridor leads to an unroofed area without a door somewhere in between, that may be the problem.

I put a door in an that seemed to fix the problem.  I've never had to use a door in that situation before though, any idea why it is suddenly happening now?

Can you reproduce this in a vanilla game? 

If yes, please describe the exact steps and include the log file.

If not, it's mods related and will be moved into Mods Bugs.  We'll still need the steps to reproduce, including your full mod order (or a reproducer set).

I can't seem to reproduce this in a vanilla game.  Sorry about that, I didn't realize there was a separate mod bug forum.

[milon]

Okay, moved to mod bugs.  And it's a relatively new subforum, so don't worry about it.

It would still be helpful to see the mod list if you want to track this further.