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oxfrxLOCAL m.loXFRX
m.loXFRX = XFRX("XFRX#INIT")
?oxfrxm.loXFRX.getVersion()

oxfrxm.loXFRX = XFRX("XFRX#LISTENER")
?oxfrxm.loXFRX.getVersion()

LOG file

Another thing that can help us to find out what's wrong is a log file: Before calling SetParams(), please add loSession.initLog(). Then, when you run XFRX next time, _XFRX.log file will be generated in the default directory. This file contains all errors that are trapped during XFRX execution. Attaching this file to the email is a big help for us. The alternative method is setLogFile(). 
Error messages are print to "Output Windows" too (since XFRX 15.8).

OxfrxLOCAL m.loXFRX
m.loXFRX = XFRX("XFRX#LISTENER")
Oxfrxm.loXFRX.setLogFile("xfrx.log")
m.lnRetVal = Oxfrxm.loXFRX.SetParams("test.pdf",,,,,,"PDF",,,,.T.)
IF m.lnRetVal = 0
   REPORT FORM test objectOBJECT oxfrxm.loXFRX
ELSE 
  ?Oxfrxm.loXFRX.ErrorMessage(m.lnRetVal)
ENDIF

Diagnostic mode 

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