Tds return filling

HELLO EVERYONE,

WHILE I WAS PREPARING TDS RETURN,I FACEING PROBLEM IN CRETING FILE.

FIRST I DOWNLOAD RPU VERSION AND E-FILE VALIDATION UTILITY FROM NSDL SITE.

THEREAFTER I FILL RPU (26Q) CHALLAN N ANNEXURES..NOE I SAVE IT AS 26Q1.

WHEN I RUN FILE VALIDATION UTILITY 1ST OPTION IS SELECT FUV FILE..

SECOND OPTION IS ERROR FILE

THIRD OPTION IS UPLOAD FILE...NOW WHAT TO DO......N SAME PROBLEM IN CRETING FILE ALSO.

IS THIS ERROR IS OF FILE EXTENSION OR ANYTHING ELSE.............REPLY FAST