HUAWEI LYO-L21 invalid imei
 

IMPORTANT NOTE: DON'T CONNECT MULTIPLE ANDROID DEVICE IN USB DEBUGGING MODE AT SAME TIME!
2017-06-10 - 19:49:08 : Waiting For Device... OK[WinUSB]
2017-06-10 - 19:49:10 : Please Tap on 'OK' in 'Allow Usb Debugging;' Pop-up on Device Screen!
2017-06-10 - 19:49:12 : Device Status: [ONLINE]
2017-06-10 - 19:49:12 : Model : HUAWEI LYO-L21
2017-06-10 - 19:49:12 : Manufacturer : HUAWEI

2017-06-10 - 19:49:13 : Serial No. : TUBBBCB722110041
2017-06-10 - 19:49:13 : BaseBand Version : MOLY.LR9.W1444.MD.LWTG.MP.V42.P40,MOLY.LR9.W1444.M D.LWTG.MP.V42.P40, 2016/10/12 10:30

2017-06-10 - 19:49:13 : SW Version : LYO-L21C577B124

2017-06-10 - 19:49:13 : Custom Version :

2017-06-10 - 19:49:13 : Android Version : 5.1
[HUAWEILYO-L21
]
2017-06-10 - 19:49:13 : Built Date : Thu Dec 8 18:22:32 CST 2016

2017-06-10 - 19:49:24 : Checking Root Permission... OK
2017-06-10 - 19:49:34 : Prepairing... OK
2017-06-10 - 19:49:35 : Prepairing IMEI(S)... OK
2017-06-10 - 19:49:57 : Repairing IMEI(S)... OK..OK..OK
2017-06-10 - 19:50:18 : Writing IMEI(S)... OK..OK
2017-06-10 - 19:50:18 : Rebooting to Normal Mode... OK
2017-06-10 - 19:50:18 : Stopping ADB Service... OK
2017-06-10 - 19:50:18 : Operation Time: 00:01:10

invalid imei ?????

write nvram and try again
Or
Check by hde pack

nvram not bacup

plase update nv ram LYO L21