Here's an example of the starvation bug. Food is available (not much and not all cooked) but the colonist just stays in one place and starves to death. Ive seen this before with the colonist caught on a grave, but the closest object he could be caught on is the chapel chair.
I've noticed colonists have developed the ability to get stuck on construction ghosts of items not yet built, doesn't happen often but has happened enough that I'm entirely certain that it's the blueprints they're getting stuck on as in all cases removing the blueprint solves the problem. Could it be that's what's happening with you?
In this case the chapel was fully built. Im thinking the actual hang up may be on the desire for whatever the chapel provides not being met, despite there being a crew assigned to chapel.
I am getting this bug again. Definitely a situation where a colonist is seeking a confession or something from the vicar, and that need not being fulfilled for whatever reason. Have a vicar (with a workcrew) who preaches at fully built chapel. If nothing else, it shows the dedication these guys have to Cog. They'll starve to death rather then continue a life without absolution. Now, if I can only figure out how to corrupt and bend this dedication to my evil will...
