AM2634: flashing error while flashing through UART_Uniflash.py

Hi Ti Experts,

I am trying to flash my AM263x Eval board using uart_uniflash tool.

while flashing i am getting the below error.

I am using the below files for flashing

flash writer Binary - sbl_uart_uniflash.release.tiimage

BootLoader Binary - sbl_qspi.release.tiimage

AppImage Binary - Appimage from GPIO Led blink example project.

while flashing I am choosing the boot mode switch to UART mode.

I have tried the above steps with different versions of MCU+SDK, result is always same. is there something i need to take care of.