All of the sudden I cannot make calls, just nothing happens

Hi there, I have a serious problem with my FP2. Yesterday, my phone ‘rebooted’ without any notice (i only found out when i picked up my phone that i had to enter myPIN again…) and since then i cannot make phone calls anymore. I do receive calls without problem, but when i try to phone someone, it starts normally but then stos before there is any tone. I just stops and i’m back to the overview of recent calls and my latest call is not in there.

I have done online research for the cause, and i found the problemshooter in case there’s the text 'cannot make connection (or something like that)" but in my case there is no notification whatsoever. And I don’t use 2 SIMcards.

So… i’m curious if anyone can help me?

Hope to hear from you