This is the description of the error from the Norton Guide:
DBFNTX/1003 Open error (index)
Default Behavior: Program continues without opening the index file (.ntx).
Explanation: The specified index file could not be opened.
Action: Check to make sure that the specified file exists. If the file is not in the directory where the application runs, use SET DEFAULT or SET PATH to make the file accessible or specify the full path name where the file can be found. In a network environment, make sure the
application has the necessary rights to access the file. If the file is available only for read access, use the READONLY clause on the USE or SET INDEX command.
CA-Clipper's default error handler (Errorsys.prg) will set NETERR() to true (.T.) and will ask DBFNTX to default if the error was due to a sharing violation on the network.
See Also: USE command, SET INDEX command, Network Programming chapter in the Programming and Utilities guide
What is the server, is that running out of file handles?
If any 12th computer errors, then it must be the server that is causing the problem.
Hope this helps a bit.
HotEye