Failed to install patch 8487427 for EBS 12.1.1

Question

Hi, I have a problem installing the patch 8487427 for EBS 12.1.1
the install log is:
Time is: Tue Nov 22 2011 13:09:50
FAILED: file MTH_PROD_MTL_CONSUMED_STG.xdf on worker 2 for product mth username APPS.
Time is: Tue Nov 22 2011 13:09:51
FAILED: file MTH_PROD_MTL_CONSUMED_TXN_STG.xdf on worker 1 for product mth username APPS.
Time is: Tue Nov 22 2011 13:09:51
There are now 169 jobs remaining (current phase=A2):
1 running, 1 ready to run and 167 waiting.
FAILED: file MTH_PROD_MTL_PRODUCED_TXN_STG.xdf on worker 4 for product mth username APPS.
Time is: Tue Nov 22 2011 13:09:51
FAILED: file mth_tag_readings.xdf on worker 3 for product mth username APPS.
Time is: Tue Nov 22 2011 13:09:52
ATTENTION: All workers either have failed or are waiting:
     FAILED: file MTH_PROD_MTL_CONSUMED_TXN_STG.xdf on worker 1.
     FAILED: file MTH_PROD_MTL_CONSUMED_STG.xdf on worker 2.
     FAILED: file mth_tag_readings.xdf on worker 3.
     FAILED: file MTH_PROD_MTL_PRODUCED_TXN_STG.xdf on worker 4.
ATTENTION: Please fix the above failed worker(s) so the manager can continue.
Current time is: Tue Nov 22 2011 13:09:52
and adwork001.log is:
================================================================================
Applying XDF file : C:\oracle\PROD\apps\apps_st\appl\mth\12.0.0\patch\115\xdf\MTH_PROD_MTL_CONSUMED_TXN_STG.xdf
================================================================================
Table Name is MTH_PROD_MTL_CONSUMED_TXN_STG
Table exists in the target database
Checking for differences
Number of columns for the table in the xml file is 30
INFO: An additional column WORKORDER_FK exists in the target database
The table MTH_PROD_MTL_CONSUMED_TXN_STG is missing the column WORKORDER_FK
Warning: The missing column is NOT NULL and there is no default value to apply
Adding a nullable column with the statement
Executing statement
ALTER TABLE MTH.MTH_PROD_MTL_CONSUMED_TXN_STG ADD ( WORKORDER_FK VARCHAR2(240) NULL )
Start time for statement above is Tue Nov 22 13:09:51 GMT-04:00 2011
End time for statement above is Tue Nov 22 13:09:51 GMT-04:00 2011
Error in executing statement ALTER TABLE MTH.MTH_PROD_MTL_CONSUMED_TXN_STG ADD ( WORKORDER_FK VARCHAR2(240) NULL )
Error message is ORA-01430: la columna que se esta agregando ya existe en la tabla
Error code is 1430
Updating task with status 1
AD Worker error:
The utility FndXdfCmp returned error for the above task.
AD Worker error:
The above program failed. See the error messages listed
above, if any, or see the log and output files for the program.
Time when worker failed: Tue Nov 22 2011 13:09:51
thanks for your help

Answer 1

Did you apply the patch with "options=checkprereq" as mentioned in the patch README file to ensure that all necessary prerequisites have been applied successfully before applying this patch?
Thanks,
Hussein