CRC error in bootloader with setting of XML

Hi,

I have known a case to raise CRC error in secure bootloader with using \nRF5_SDK_17.0.0_9d13099\examples\dfu\secure_bootloader\pca10100_s140_ble

I enabled a nrf_log to know a sequence DFU. Then I had to add some settings in .emproject, sdk_config.h and flash_placement.xml.

When i added section of 'log_backends' like below, I saw CRC error.

I resolved it by adjusting a line section of 'log_backends' like below.

I want to know what you think about this. What different...

 

thanks in advance for any helps.