C7000 E:ensure_path_unmounted failed to unmount /efs (device or resource busy)

C7000 after flash E:ensure_path_unmounted failed to unmount /efs (device or resource busy) i want to change CHC firmware to TGY hong kong firmware
i want to fix play store, 1st unlock crom service then flash but after flash
show me error in recovery now phone condition stuck in logo phone charging every thing okay.

solution plz.