I can no longer administer my brdmgr 3.7 server running on nw6.

When I click on the bordermanager setup tab in nwadmin, it gives me a
screen which says:

The NDS schema cannot be extended.

NDS error 601.

Server is running nw6sp4 with bm37sp3. In other words, I've tried everything I can think of.

I wonder if this has anything to do with the fact I upgraded another
netware server in the tree to nw6.5??

Looking for suggestions or solutions.