[Q] [q] cant make calls on cm 10.2 jelly bean 4.3.1 on htc explorer topic

Please help me DEVS. I am UNABLE to MAKE CALLS after flashing CM 10.2 JELLY BEAN 4.3.1 on my HTC EXPLORER PICO.but everything is fine other than that.I flashed it twice but no use.

I NEED QUICK HELP PLEASE.SUGGEST ME.WAITING FOR YOUR REPLY. :crying::crying::crying: