myGrid have identified a bug T2-1989 affecting Taverna 2.3.0 which means that Taverna is not able to install third-party plugins.

Technically what happens is that one of the Maven repositories used by Taverna to retrieve plugin libraries have recently relocated and returns a 302 Found redirection and an HTML error message.

Taverna incorrectly stores this HTML instead of retrieving the plugin's POM/JAR file from the repository from the plugin provider, thus preventing plugin installation. Taverna would in this case give an error message like POMFailed and SAXParseEception in your Taverna log file, although no error message might appear in Taverna's window.

ERROR 2011-09-05 16:10:20,079 (System.err:139) - [Fatal Error] :1:50: White spaces are required between publicId and systemId.
WARN  2011-09-05 16:10:20,079 (net.sf.taverna.raven.repository.impl.ArtifactImpl:85) - XML SAX error for C:\Users\stain\AppData\Roaming\taverna-2.3.0\repository\com\example\example-activity\0.0.2-SNAPSHOT\example-activity-0.0.2-SNAPSHOT.pom
org.xml.sax.SAXParseException: White spaces are required between publicId and systemId.
	at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
	at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
	at javax.xml.parsers.DocumentBuilder.parse(Unknown Source)
	at net.sf.taverna.raven.repository.impl.ArtifactImpl.readAndParseXML(
	at net.sf.taverna.raven.repository.impl.ArtifactImpl.readXML(

myGrid have released an update the to two components of Taverna referring to this repository. This update does not include any new functionally or other bug fixes.

You should install this update if you are planning to install 3rd party plugins in Taverna 2.3.0.

Before installing any plugins:

  1. In Taverna's menu, go to Advanced -> Updates and plugins.
  2. "An update is available for this plugin" should appear in blue for External tool service and Services.
  3. Select External tool service and click Update, then OK at the notice.
  4. Repeat for Services
  5. Click Close
  6. Exit Taverna using File -> Exit or Taverna -> Quit.
  7. Restart Taverna and install the plugin as normal

If you have already installed the plugin, you will after this need to clear your local "repository" folder to force Taverna to re-download the plugin. Note: The folder to delete is not the repository folder of your Taverna installation directory, but from your Taverna home directory.

  1. From Taverna, click Advanced -> Show logs and data folder (see Taverna home directory)
  2. A Windows Explorer/Finder/Gnome window should appear
  3. Exit Taverna using File -> Exit or Taverna -> Quit
  4. Find and delete the folder repository
  5. Start Taverna again
  6. The splashscreen should indicate that plugin libraries are being downloaded and might take a while on first startup
  7. Go to Advanced -> Updates and plugins to check that your plugins are installed.