Kevin,

additional to Sergeys.
>1) Is the Replace feature of the Code References tool reliable?
I use it in prg's. Sometimes it works for vcx / scx but it has problems there.

It's mostly based on the following
1) vcx holds junk records. That are records that are somehow snippets from classes. One will see those when the search might bring up double results for some queries. After a while those records are on top of the vcx table. One might delete them there. The other way to get rid of them is to copy all classes to an other empty vcx, delete the old one and rename the new.

2)UNIQUEID is not unique. This happens if you copy a class. The replace relies on UNIQUEID. You need to make the field unique.
Something like.

USE your.vcx
REPLACE;
 UniqueID WITH SYS(2015);
 FOR PLATFORM='WINDOWS'
USE

will do.

Anyway, its a good idea to make a backup before Code References Replace.

Agnes