My iPhone5 with IOS704 regularly returns me the error “Invalid SIM” & “No SIM card installed”.
After restarting the phone… the error disappears.
But after a while the error returns…
Here are my findings while troubleshooting the issue:
1. restart phone… ok, but problem returns
2. airplane on/off doesn’t work
3. try network reset: Settings>General>Reset>Reset Network Settings (returns to factory network settings) > no solution
Network Reset returns the phone to normal service, but after a while the problem returns again…
4. next… replace nano-SIM: problem solved !