All posts in the topic Log Files and GroupServer (Short link)

From: Michael JasonSmith Date: Jul 04 02:38 UTC Short link

GroupServer and Zope keep an activity log. The log can be found in
  $INSTALL/var/log/instance.log
(Where $INSTALL is the directory that GroupServer is installed in.) GroupServer
messages are always preceded by the module name, and normally list
  * The site
  * The user, and
  * The group
associated with the event. Where possible, GroupServer lists name of each
object, with the ID following in brackets.

For debugging purposes, I usually find it useful to run Zope in foreground
mode:
  $INSTALL/bin/instance fg
It dumps out a lot of data to the terminal :)