Lenovo a369i no imei after flash of new firmware in sp tool it shows Imei null?

I tried a lot of solution I tried using engineering mode like I see on zoppo mobile in youtube but the send at command doesn't work, I tried also the mtk tool I root it even mobile uncle doesn't work even volcano box doesn't work even if the box says Imei write successful it still shows invalid, I can't even text and call it is useless please help me I'm so sad I search in all internet but I can't find any solution please help me. Huhuhu…