I'm trying to add a user to a group. So, on the "One Group" page for the group I'm interested in I select "Add Member", then "User Profile", then "select an existing User from the system", then I select the first user and hit "Submit". The system then produces a "Database operation "0or1row" failed (exception NSDB, "Query was not a statement returning rows.")" error.

The logs show that this is happening when this

select user_profile__new(NULL,NULL,'2669','2112','approved',NULL,NULL);

is called. It produces this error:

ExecAppend: Fail to add null value in not null attribute object_type

This is odd because just a few lines higher I can see the object type explicitly set to "user_profile":

Notice: BEN_ACS_SUBSITE: user_profile; object_id_one object_id_two member_state object_type

Which comes from 829 of acs-subsite/tcl/package-procs.tcl

# Ben's temporary hack
lappend pieces object_type
ns_log Notice "BEN_ACS_SUBSITE: $object_type; $pieces"

You've hit a bug in user-profiles-create.sql (typo on my part). I fixed this yesterday (see rev 1.4), so update your cvs and reinstall. Note, you may still get an error if you're trying to add your user profile to a group and not an application group (the server log will have a nice message about violating the relationship constraints).