Can't get olink to generate a working link between books in a set

Dear friends,

I am having problems getting olinks to correctly generate links between books in a set in HTML output. I want to be able to output independent books that contain references to content in other books, and when the books are produced as part of a set, these references should become links in HTML output.

I am using oXygen XML Editor 18.0 that uses Saxon to generate HTML output. I've set up project files for two books (srr-book.xml and dos-book.xml) and one set (test-set.xml) as a test. I have inserted one olink in the srr-book that points to a section in the dos-book.

The test-set.xml document looks like this:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE set [

<!ENTITY % commonentities SYSTEM "../../Source/Common/commonentities.ent" >

%commonentities;

<set xmlns="http://docbook.org/ns/docbook" version="5.0" xmlns:xi="http://www.w3.org/2001/XInclude"

xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="test-set">

<info>

</info>

<xi:include href="">

</set>

The olink markup in the srr-book.xml document looks like this:

<para>Not to be confused with <olink targetdoc="dos-book" targetptr="dos-overview">Overview Link</olink>,which is something altogether different.</para>

When the test-set.xml document is processed, oXygen gives this error message:

[xslt] Error: unresolved olink: targetdoc/targetptr = 'dos-book/dos-overview'.

And the HTML output where the link should be looks like this:

<p>Not to be confused with <span class="olink">Overview Link</span>, which is something altogether different.</p>

The olinkdb.xml files for the books and the set are as follows:

- srr-book.xml:

<?xml version="1.0" encoding="UTF-8"?>

<targetsetinfo> Description</targetsetinfo>