Huawei P8.Can't make or recieve calls though 4g works fine.

[AC Question]

Hey, my name is Chris, i'm from Greece and I recently got a Huawei p8 lite ale l21 and i can't make or receive any calls. When I trying call someone i get a "mobile network not available". In dual sim setting i can see my sim working in slot 1 and i have full signal and 4G perfectly working all the time. Also slot 2 is totally useless as when i tried to place my sim there i did not have even signal.
I have searched around the web a little bit but i have not find something really helpful. Any ideas?
It will be helpful to change my ROM to a custom?My current version is C432B170. That was the first thing that i thought but i m not very familiar with that kind of stuff

 

[dpham00]

Does the sim that you have now work in another phone?

Have you tried another sim card?

 

[nkanyiso Shangase]

I have been using my P8 for like 10 month and suddenly it complaining about mobile network id not available , Ave try my sim card into a different phone and it working correct , mostly they suggest to take out bettry which is imposible for this phone

Can anyone help