Xmodem protocol error for eMMC

I have a board from a company that uses the A388 eMMC. I want to put it in my clearfog pro board and flash it with standard linux to repurpose the board. Following the instructions from the link below regarding installing software to eMMC, I get to line 17 where it says to kwboot and the output I get is this:
Sending boot image…
0 % [+xmodem: Protocol error

Am i going about this wrong? I am able to screen to the board when it boots and able to see it trying UART so I am thinking my hardware setup is correct.

https://solidrun.atlassian.net/wiki/spaces/developer/pages/287342998/A38X+Debian

You need to disconnect your terminal application when using kwboot. You can use the built in terminal functionality of kwboot to access u-boot immediately after loading it.

If I follow what you are saying, you are suggesting to not cause conflict with screen and kwboot. I used screen to confirm I had some sort of output and that i was using the correct serial port. I killed screen prior to kwboot. Am i following you correctly or are you going after something different?

okay, so your console program is not connected to the serial port. In that case can you post the full kwboot command you are using?

I get hung up when running the command below.
./kwboot -t -b u-boot-clearfog-base-uart.kwb /dev/ttyUSB0