Cannot make phone calls

Of late, increasingly often, I cannot make calls with my FP2.
When I select a contact, or a number, simply nothing happens. Not the popup to select a sim-card. No error message. Just nothing.
Same when I key in the number myself: after pressing the call-icon, again, nothing happens.
When I reboot, I can call again, but after a number of calls, the misery starts again.

Anyone any clue? Since I want to use my phone mostly to make calls (I’m quite oldfashioned in this respect, maybe) this is of course terribly annoying…

Help appreciated!

2 posts were merged into an existing topic: Two SIM cards - can’t make/receive calls when both are turned on - Workaround: Wait 5 seconds