Determine Worker Eligibility for Performance Document not working

Summary

Determine Worker Eligibility for Performance Document not working

Content

Hi Experts 

Need help on FF (Participation and Rate Eligibility)

I have written a simple FF that returns Y 
Attached  the FF to a eligibility profile which is attached to Performance Temp
When i try to run the "Determine Worker Eligibility for Performance Document" 
it gives the below error 
"The selected worker is not eligible for the performance document "
but when i remove the FF from the eligibility profile and run the process the employee is getting selected. 

it is clear the formula is what restricting the employee.
i also tried the log ESS_LOG_WRITE to make sure the return from FF is Y.