DITA Map WebHelp Transformation Fails (Duplicate Topic References Found)

Problem

DITA Map WebHelp transformation fails with a message that indicates duplicate topic references were found.

Solution

By default the WebHelp transformation uses the force-unique parameter set to true to force the transformation to create unique output files for each instance of a resource when a map contains multiple references to a single topic. However, there are cases when this feature does not work as expected and the duplicate topic references are not handled properly.

To solve this issue, you should manually set a unique copy-to attribute on any duplicate topic reference that was not handled automatically by DITA-OT:

<map>
...
  <topicref href="../topics/MyTopic.dita"/>
...
  <topicref href="../topics/MyTopic.dita" copy-to="../topics/MyTopic-2.dita"/>
</map>