'group_' Error when assigning roles to users and/or groups
As of this writing (2005-06-07), Debian/Sarge ships with Plone 2.0.4 combined with GRUF3. This combination will cause a 'groups_' error whenever trying to assign Roles to Groups and is documented in Ingeniweb's GRUF3 product:
There's a bug in Plone's folder_localrole_form in Plone 2.0.x, preventing it to work with GRUF 3. That's because group name is passed to GRUF's methods instead of group id. To solve this, you either have to fix the form by yourself (replace group_name by group_id), or wait for Plone 2.1 ;) A sample fixed form is provided in the gruf_plone_2_0 skin folder (which is NOT installed by default)."
The solution to this is to obtain the folder_localrole_form from either SVN or CVS and use that template instead of the one that ships with GRUF3.
A bug report has been filed with the package maintainer but it doesn't look like the fix made it into Sarge before its release today.