Please retry with the new RC1 release, there were several fixes in the Feature Source preview relating to Extended Feature Classes / Feature Joins - Jackie -- View this message in context: http://osgeo-org.1560.n6.nabble.com/MG-2-4-b1-join-error-tp4984823p4987082.html Sent from the MapGuide Users mailing list archive at Nabble.com.