4.3.0-fuse-02-00 should use karaf 2.0.0-fuse-01-00, the error you saw is can't find karaf 2.0.0-fuse-00-00 features.xml.
Did you ever change something in etc/org.apache.karaf.features.cfg?
Yes, I changed the name in the apache-karaf-2.0.0-fuse-01-00-features.xml file that is inside ~/apache-servicemix-4.3.0-fuse-02-00/system/org/apache/karaf/apache-karaf/2.0.0-fuse-01-00
As apache-karaf-2.0.0-fuse-01-00-features.xml was constantly searching for 2.0.0-fuse-00-00 features.xml, I changed 2.0.0-fuse-01-00 features.xml in config.properties to 2.0.0-fuse-00-00 features.xml.
But previously when apache-karaf-2.0.0-fuse-01-00-features.xml was as it is(ie 2.0.0-fuse-01-00 features.xml.) it is giving the same error.
Pls refer attached screenshots.