Export .tf into .lef file

 I have converted virtuoso .tf into lef file from file > export > LEF. But when I use it with encounter as a tech lef, there are a lot of  errors like the following

**ERROR: (ENCLF-268):    " There is no spacing table defined bewteen cut class
'square' and 'square' in layer 'VIA6'. It may cause certain commands not working"

and

**ERROR: (ENCLF-53):  " The layer 'VTL' is not found in the database.
A layer must be defined before it can be referenced."

Am I following the right procedure of converting .tf into .lef?