Admin abilities lost

I have a client using Netware 5.X/50 users. They have 2 issues, but the main one is that they have lost admin abilities. It appears that all groups have lost memberships including the admin group. The user admin has disappeared completely and nobody is a member of administrators. Because of this no users can be created or edited or put into groups. Oddly, the existing users seem to have their same permissions, but not being able to create users or change permissions on existing users is a big problem. Any ideas?