PeopleSoft - AppEngine

Application Engine Error

i am getting the below error while running Application Engine Program .

Could you tell me what would be the reason ....

File: E:\pt84920b-retail\peopletools\SRC\PSAPPENG\aebuf.cppSQL error. Stmt #: 574 Error Position: 0 Return: 8010 - [Microsoft][SQL Server Native Client 10.0][SQL Server]Invalid column name 'PROCESS_INSTANCE'.

Scheduled AE program...

I hav to develop a AE program with the below functionalities.
i) The administrator should have the ability to rerun the process without having to cancel prior failure runs
ii) The process should be scheduled to run once a day. The administrator should also be able to run the process multiple times a day on an adhoc basis.