Encounter to OA error using OSU Standard Cells library

Hi.

I want to ex****t a Encounter design to a OA cellview. To do this,
first a used cdb2oa in the cdb library provided by Oklahoma State
University. Then I converter the cdb library to a OA library using the
following tutorial:
http://www.chiptalk.org/modules/wfsection/article.php?articleid=14

But when I will ex****t the cell, the following errors appear:

encounter 3> ----- oaOut ---------------------------
OA Db rev : 99
FE 0.001 microns/db , OA units = 1000 x MICRONS g2 is 1000 db/micron  -
> conversion factor is 1:1
Special routes: 0 strips, 0 vias
**ERROR: (SOCOAX-448):  Could not create OA database Invalid viaDef :
TIMER: oaOut total process: 0h 0m  0.06s cpu {0h 0m 0s elapsed} Memory
= 0.0
**ERROR: Couldn't save design into OA database.


Is this a .lef file error? A OA tech file error? I'm using the
NCSU-1.6 PDK and OSU 2.7 SCLIB.