I figured this out.. instead of flashing by sdk 1.2, first tried with 1.1.3. and then updated to sdk 1.2.
I hope this helps you

@Wei-Cui
How did you wipe the /data?

While flashing the voxl2 I am getting this error. Do you guys have any recommendation?

[WARNING] This system image flash is intended only for the following
          platform: VOXL2 (m0054) 

          Make sure that the device that will be flashed is correct.
          Flashing a device with an incorrect system image will lead
          the device to be stuck in fastboot.

Would you like to continue with the VOXL2 (m0054) system image flash?
1) Yes
2) No
#? 1
[INFO] checking partition system::0xD3B5D7000
[INFO] {system::0xD3B5D7000} partition returned size {0x1A435F3000}, expected {0xD3B5D7000}
[WARNING] Partition layout was found to be incorrect, this requires
          flashing the full partition table. Flashing the partition
          table will also flash every partition causing all data on
          the device to be lost.

When doing a full flash, make sure to backup any important files

Would you like to continue with the full wipe/flash now?
1) Yes
2) No
#? 1
[INFO] Found all required files

Flashing: modalai_conf | m0054-conf-fs.ext4
[--------------------------------------------------------        ]( 88%)

[ERROR] Failed to flash partition: modalai_conf

target reported max download size of 805306368 bytes
sending 'modalai_conf' (5176 KB)...
FAILED (remote: Error: Last flash failed : Volume Full)
finished. total time: 0.000s

@tom Thank you so much!
I was having the exact same problem with @marian.
I could connect to the voxl via ssh but could not via adb shell.
But could solve it after removing the /etc/udev/rules.d/51-android.rules.
Try to remove the file, who are facing the same problem with me.