Hi,
I have a table named REGOPER_PART with 18,000 records. When trying to create
a foreign key that DID NOT exist, I get:

This operation is not defined for system tables.
unsuccessful metadata update.
STORE RDB$RELATION_CONSTRAINTS failed.
attempt to store duplicate value (visible to active transactions) in unique
index "RDB$INDEX_12".

When trying to check Indexes for this table using IBConsole, I get:
SQL ERROR CODE -204
Ambiguous field name between table RDB$INDICES and table RDB$INDEX_SEGMENTS
RDB$INDEX_NAME

I gbaked and restored it, and the problem is still there.

whats wrong?
Guillermo