Another question - Do you have a MYCAR.mas anywhere in your APP PATH?

If you do then it may point elsewhere and the initial data extract is getting written to where that is, the FILEDEF .... (APPEND is repositioning it.

Try this -

FILEDEF MYCAR DISK MYCAR.FTM
TABLE FILE CAR
SUM RCOST/I9
BY COUNTRY
ON TABLE HOLD AS MYCAR FORMAT ALPHA
END
-RUN
FILEDEF ADD_DATA DISK MYCAR.FTM (APPEND
-RUN
-WRITE ADD_DATA additional      123
-RUN
TABLE FILE MYCAR
PRINT *
END

Thanks Tony, now it works

Glad that it does. I take it the reason was a spurious MYCAR.ftm somewhere?

T