After complete installation of JBT 3.1.0 GA #56 this error occurs:

eclipse.buildId=unknown
java.version=1.6.0_17
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=linux, ARCH=x86, WS=gtk, NL=en_US
Framework arguments: -product org.eclipse.epp.package.jee.product
Command-line arguments: -os linux -ws gtk -arch x86 -product org.eclipse.epp.package.jee.product

Error
Fri Apr 02 09:24:14 CEST 2010
Project facet group group.birt.chart.runtime has not been defined. It is used in plugin org.eclipse.birt.integration.wtp.ui.