Can anyone suggest where to begin debugging this? I don't yet have the XSL chops to do more than vaguely guess what's happening in the lines referenced in the error messages. I'm running Oxygen 11 in Eclipse 3.6 on Ubuntu 9.10. (And cross-posting to the XEP list.) Here's what seems to be the relevant output: transform.topic2fo: [dita-version] Search finished [detect-lang] Lang search finished [echo] Using document.locale=en_US [echo] [index-preprocess] [INFO] IBM ICU4J Collator is not found. Default Java Collator will be used [index-preprocess] [INFO] IBM ICU4J Collator is not found. Default Java Collator will be used [java] [ERROR] Topic reference (href : #null) not found ! [java] [ERROR] Reference may be incorrect. Please correct your ditamap or bookmap file. [java] Processing terminated by xsl:message at line 110 in root-processing.xsl BUILD FAILED /home/tkuster/eclipse/plugins/com.oxygenxml.author_11.1.0/frameworks/dita/DITA-OT/build.xml:59: The following error occurred while executing this line: /home/tkuster/eclipse/plugins/com.oxygenxml.author_11.1.0/frameworks/dita/DITA-OT/build.xml:394: The following error occurred while executing this line: /home/tkuster/eclipse/plugins/com.oxygenxml.author_11.1.0/frameworks/dita/DITA-OT/demo/fo/build.xml:180: The following error occurred while executing this line: /home/tkuster/eclipse/plugins/com.oxygenxml.author_11.1.0/frameworks/dita/DITA-OT/demo/fo/build.xml:308: The following error occurred while executing this line: /home/tkuster/eclipse/plugins/com.oxygenxml.author_11.1.0/frameworks/dita/DITA-OT/demo/fo/build.xml:254: Java returned: 1 Many thanks for any suggestions. Ted Kuster CollabNet