Error: operation failed during the erase operation

Hi everybody

I m working on the board with Arria GX. I m having problem while programming using the Active Serial mode(EPCS64N device). In AS mode while programming i was getting the error as "Verification failed for device number 1". I thought may its a problem with the EPCS64, so i replaced it. But now i m getting error during the erase mode as "Operation failed".

need help

regards,

bhandari