Here is another situation, this time with LOG-OUTPUT on Lispworks.
On Lispworks, when calling CREATE-SERVER is called from the IDE, *LOG-OUTPUT* gets initialized to the listener pane's output stream. When this listener goes away, (say the window is closed), *LOG-OUTPUT* points to a non-existant stream, and subsequently writing to this stream causes errors. (On LWL this can eventually crash the lisp process).
[This dept. (logging errors incorrectly) has been a source of headaches for me for a long time. The changes in code the dept. have only made maintaining workarounds more difficult, and have not satisfactorily addressed the failure modes (under which it fails). I suggest that Slime should report error-producing errors only on a file stream over which it has total control.]
-- Madhu