You may see this error when you first install Contour:

java.lang.LinkageError: JAXB 2.0 API is being loaded from the bootstrap classloader, but this RI
(from jar:file:/somedirectory/jaxb-impl.jar!/com/sun/xml/bind/v2/model/impl/ModelBuilder.class)
needs 2.1 API. Use the endorsed directory mechanism to place
jaxb-api.jar in the bootstrap classloader.

This only happens to early versions of JDK 1.6 which embeds JAXB2.0.  To fix it you have the following options:

1. Update JDK to the latest 1.6.X.

OR

2. Put the version of jaxb-api.jar your are using to JDK_HOME/jre/lib/endorsed. Create the endorsed folder if necessary.

You can check the version of the embedded JAXB library with the following command

%xjc -version

Here is a link to the issue:
http://blog.spaceprogram.com/2007/05/how-to-fix-linkageerror-when-u...