verify failed on onchip-memory

hello everyone

when i try to download elf with command "nio2-download -g xxx.elf",it shows "verify failed between address 0x20020 and 0x2FFFF Leaving targe proessor paused" sometimes.

The address"0x20020-0x2FFFF" is belong to on-chip memory(0x20020-0x38fff).

This error doesnot occor every time,and sometimes the device can work properly.

The chip model i use is EP4CE115F23I7.

How to deal with this problem?Looking forword to your answer!