Hello,
Yesterday I got the same error as everyone in this thread:
"All telephony functions, including emergency calls, are disabled due to a communication error. To recover, you might have to reboot the device".
The strange thing that originally it was like appearing and disappearing, like I saw red line crossed SIM and then it disappeared and coverage bars appeared. Then again crossed SIM and then again coverage. Of course, I though it is SIM issue, but placing in my old E65 it worked fine.

In another discussion about the issue and there was question about IMEI - if you see the IMEI. And for my surprise - IMEI is gone. Using *#06# or just looking at settings there is no IMEI.

Phone is already out of warranty so I want to understand if there is some solution to fix or now it is only expensive WiFi device (as Wifi still works good).

Thank you.