Anyway, I've seen the same thing at times: all green. One distinct memory I have is of knowing that something was wrong, so I scanned through the first level under each main type of element. Eventually I got to seeing red. I was able to fix it that way. I can't guarantee that you won't be wasting time if you do the same, but that's my experience. Usually the problem is more obvious.
Basically, that window seems to be an assemblage of all civil elements within your working file. It's sometimes helpful to delete certain things, such as once I decided to delete something under DynamicCrossSectionSpace because it was giving me trouble, and that helped. (Of course later I found that a different series of steps would have worked too, but I wasn't aware at the moment. And that same series of steps might not work for a different problem that deleting the DynamicCrossSectionSpace.)
I'm out of guesses, but I have no memory of a corridor doing that to me. In fact, in my experience, if they go bad I can still look at Corridor Objects, though nothing happens if I make any changes. Usually, the cause has something to do with superelevation not being associated with the alignment correctly, or the terrain might be faulty, or whatever.