Yes, I've seen such things recently, normally not much of a problem, I could
solve quests once again, or become a guard member once more, because something
on Spencer had been changed. This happened while upgrading from my prevoius
0.15-SVN-something to a stable version from Debian, I think. Upgrading again to
the current git version crashed the game upon loading. I think crashed should
not happen, and can in theory be avoided if everything has reasonable initial
values which get overwritten when loading a saved game. Things missing in the
file would remain in the initial state, things no longer present would be
ignored. Renamed things could even be translated, which is of course more work.