A bit of a niggly problem with this and it all does seem to come down to conflicting .jar files.
The one causing me a problem was
org.apache.servicemix.bundles.commons-codec-1.3.0
I also had a number of older
commons-codec jars aswell. However, this had not changed from my previous working project so its a little strange how the conflict has occurred.
I resolved the problem by removing all the offending .jar files and importing the latest commons-codec jar as deployed with Modeller version 7.13 into the project Userlib directory.