>A single cursor cannot have two fields with the same name.

Partially correct. The SQL engine will accept same named fields as input, automatically renaming them for output.

* Example:
CREATE CURSOR foo1 ( id i, field1 c(10) )
INSERT INTO foo1 values(1, "Hi, mom!")
CREATE CURSOR foo2 ( id i, field1 n(4) )
INSERT INTO foo2 values(1, 10)

SELECT a.id, b.id, a.field1, b.field1 ;
    FROM foo1 a INNER JOIN foo2 b ON a.id = b.id ;
    INTO CURSOR foo3

BROWSE LAST NOWAIT

>cFieldN is coming from both aliases according to the error message. Was a new field added recently?

The actual code was redacted for publication on UT. The real field names are not as indicated, but the gist of the message is as indicated.