error generated during bit-back of ns02 yocto

[pragnesh036]

I will follow this manual to bit back ns02 kernel (https://exorinternationalspa.sharepoint.com/sites/Downloads/Shared%20Documents/Forms/AllItems.aspx?originalPath=aHR0cHM6Ly9leG9yaW50ZXJuYXRpb25hbHNwYS5zaGFyZXBvaW50LmNvbS86Zjovcy9Eb3dubG9hZHMvRWhxaURIdlNQQXBKbllPRTYxV1d3MUFCOGZld3NSU2hXbUM3enF1eUx6bGs2Zz9ydGltZT1MSk5obV9FWTJVZw&id=%2Fsites%2FDownloads%2FShared%20Documents%2FEXOR%20Embedded%2FOpenHMI%20nS02%20kit%2F5%2E0%2FUser%20Manual%2FExor%2DEvaluationKit%2DUserManual%2Dv1%2E12%2Epdf&parent=%2Fsites%2FDownloads%2FShared%20Documents%2FEXOR%20Embedded%2FOpenHMI%20nS02%20kit%2F5%2E0%2FUser%20Manual)
after this command bitbake core-image-exor-x11
i am geting error like
ERROR: linux-fslc-mx6-rt-4.1-2.0.x-r0 do_fetch: Fetcher failure: Unable to find revision a59fac9 in branch 4.1-2.0.x-imx-RT even from upstream
ERROR: linux-fslc-mx6-rt-4.1-2.0.x-r0 do_fetch: Fetcher failure for URL: 'git://github.com/ExorEmbedded/linux-us03.git;branch=4.1-2.0.x-imx-RT'. Unable to fetch URL from any source.
ERROR: linux-fslc-mx6-rt-4.1-2.0.x-r0 do_fetch: Function failed: base_do_fetch
ERROR: Logfile of failure stored in: /home/dnk-051/STM32MPU_workspace/Exor_ns02/exor-yocto-5.0/build/tmp/work/ns01_kit-poky-linux-gnueabi/linux-fslc-mx6-rt/4.1-2.0.x-r0/temp/log.do_fetch.16283
ERROR: Task (/home/dnk-051/STM32MPU_workspace/Exor_ns02/exor-yocto-5.0/build/../git/meta-exor/recipes-kernel/linux-imx/linux-fslc-mx6-rt_4.1-2.0.x.bb:do_fetch) failed with exit code '1'

all suggestion are welcome