error of type ememoryallocerror (-14901) while in Workgroup Manager

10.4.7 server. G4 XServe.
While in Workgroup Manager, I noticed sever accounts weren’t active, with the “access acount” checkbox cleared. When I checked the box and clicked Save I get the following error for every account that’s inactive:

error of type ememoryallocerror (-14901) on line 3318 of /sourcecache/servermanagerusergeneral/servermanagerusergeneral-193.3.2/useradvancedpluginview.mm

After I clear the error dialog, the accounts appear to be activated, but when I quit out of Workgroup Manager and go back in, the accounts are still inactive.
Where do I start looking to fix this?

Mark.