When such case occurs, you need to recover firmware to the original version. Please do the following steps:

  1. Power off the device.
  2. Enter recovery menu by powering on the device while holding both Volume UP and Action buttons (video).
  3. In the menu choose "RESTORE" (not "RESET").
  4. Wait until device reboots and try to connect to wi-fi.

Sometimes "RESTORE" might not work for the first time, please repeat steps described above one more time.

After that try updating the firmware to the latest via USB (section 5.5 in the user guide: http://lametric.com/user_guide.pdf)

The latest firmware file can be found at https://firmware.lametric.com/