[tei-council] saxon problems : cannot build xsd

If I run teitoxsd online, I can turn an ODD file into an XSD one. If I try to do it in oXygen however, I cannot. The version of the framework I am using falls over with an inscrutable error message "Internal Saxon error: local variable encountered whose binding has been deleted". Poor thing. And poor me, as I would really like to do some proper testing of how well pure odd constructs map to different schema languages, and its easier in oXygen. The message rings a faint bell, but I'm having trouble reading between the chimes: can anyone advise?