C$XML stopped working

Using both 8.0.0 and 9.1.2.1 of Extend, on Windows 7, 8 and XP - on 3 different computers, calls to C$XML suddenly stopped working this week; a call to C$XML causes the runtime to "hang".  What DLL is necessary for C$XML, or what else might cause this behaviour?

Thanks

Tony

EXTCALC_COPY.zip