Xailer & OZ Software

I got the following error, but I never use any variable LNDX in my code.
Subsystem Call: BASE
System Code: 1003
Default Status: .F.
Description: Variable does not exist
Operation: LNDX
Arguments:
Involved File:
Dos Error Code: 0
Trace Through:
DBUSEAREA (0)
TDBFDATASET:OPEN (243)
SSCOMPANYSETUP (270)
TFRMLOGON:MYCHECKLOGON (88)
TFRMLOGON:BTNOKCLICK (44)
TBUTTON:ONCLICK (0)
TBUTTON:CLICK (99)
(b)XCONTROL:XCONTROL (138)
Regards,
David