LDN L21 Decrypting.....Failed: can not decrypt this lock type
 

Checking fastboot device.....OK
Reading info.....OK
Device Model: LDN-L21
Device Serial: 26EBB18323201261
Device IMEI: 867241030326823
Device Firmware: LDN-L21 8.0.0.159(C185)
Device Lock: Image is origin | Verify mode is enforcing | Check root info is risk | Lock state is lock | Root State: ROOT
Waiting for server.....OK
Reading data.....OK
Posting data to server.....OK
Waiting for server response.....OK
Unlocking device.....OK
Checking file.....OK
Processing file 1.....OK
Processing file 2.....OK
Processing file 3.....OK
Processing file 4.....OK
Switching to ADB mode.....OK
Waiting for device.....OK
Patching.....OK
Waiting for device.....OK
Waiting for Ready state.....OK
- This operation may take a long time depending on the complexity of screen lock, PLEASE WAIT
Decrypting.....Failed: can not decrypt this lock type
Operation {Reset ScreenLock} ID: 3AE6B1A777D9CAAB
Elapsed time 11:34 -- Version 2.4

Failed: can not decrypt this lock type ...

What is your device lock type ?