Default [Q] ZTE Open C Problem Help Me Please

I have a ZTE Open C, Firefox and Android 4.2.2 O (KitKat) OS say me that my IMEI number is 0, the simcard is recognized because the phone shows me the operator's name (Movistar in Venezuela in my case) but I can't make calls, when I try it the operative system shows me a message that says I'm not connected to any mobile network. I'm not sure why this happened, it is possible that it was because of an update I did in Firefox OS or because I rooted my phone in Android, someone here knows any method to restore my IMEI ?, please help to restore my IMEI and use the phone, because is completely new. I apologize for my bad english, I am using a translator. Thank you.