i did everything right, flashed keymaster and made a wipe. reboot to recovery, flash crdroid via adb sideload, it still appear this message:
serving: 'crdroid.zip' (~5%) adb: failed to read command: No error.
recovery message: Error applying update: 9 (error Code: : kDownloadTransferError)
update: fastboot flash --slot=all keymaster keymaster-op9pro.img worked for me, but not the keymaster.img in the firmware folder from crdroid official
update2: i have successfully install crdroid ROM. thank you for all of your support, it really help me alot