read nandflash fail Iin AM1808_FlashAndBootUtils_2_40

hi!
I use AM1808 and some problem with nandflash ，the source code is FlashAndBootUtils_2_40
1、when I erase a block(is a blank block) ，then read first page in the block ，return E_FAIL
I DEBUG with ccs ，found error in NAND_readPage
if ((*hNandInfo->hEccInfo->fxnCorrect)(hNandInfo,&dest[hNandInfo->dataBytesPerOp*i],readECC) != E_PASS)
{
return E_FAIL;
}

but I erase a block ,then write to first page and read this page is right。
now I use this nand driver in my app code ,but found this problem
I thank the code erase a block but not correct the ecc

does sonmething wrong with the source code in ubl with NAND_readPage?