Custom Dict, for cafrench algorithm

We are running XPP 9.3.1 on Linux using Exceed for X11 via Putty->Linux connection.

We have a JT with

Algorithm => cafrench

Main Dict => cafrench

Cust Dict => neptune

We have /opt/xyvision/sd_liz/Lstd-dict/_la_neptune.p and 1la_neptune.p with open permissions.  When running a division using the JT, we get the error below.  If I remove the neptune entry from Cust Dict the error is eliminated.  I know that I should be able to use the custom dictionary and I'm missing something obvious in the documentation...but any ideas/fixes on the below would be greatly appreciated.

***** Begin log file job.log, session number 4 *****
Exception Dictionary "la neptune" unreadable
Exception Dictionary "la neptune" is not for the "cafrench" language