Please first define code (with 'X') for release point &

What causes this issue?

You have defined a <GL:release_point>release point</> that is not yet
included in the specified <GL:release_strategy>strategy</> as a
prerequisite.

How to fix this error?

Allocate this release point to a release code. For this purpose, mark
the release point (with 'X') in the corresponding release code. You can
create a new release code or change an existing one.

Error message extract from SAP system. Copyright SAP SE.