ORA-38807: Implementation restriction: an edition can have only one child

When creating a new edition, you get:

ORA-38807: Implementation restriction: an edition can have only one child

Try this: Instead of

CREATE EDITION VERSION_10;

Use:

CREATE EDITION VERSION_10 AS CHILD OF VERSION_9;

The problem seems to be an Oracle bug in 11g and some 12c versions where the pointers to the editions are incorrect, so Oracle can’t automatically determine which edition should be the parent. Setting it explicitly resolves the problem (at least in my experience).