Introduction
After updating to 1.1.2, replacing lockdownd with proper one to get activation and signal, you might end up in having everything right except when you try to dial or send an SMS, the application crashes. This page explains why it crashes and how to fix it.
Crash of MobileSMS.app and MobilePhone.app
When dialing a number or sending an SMS and entering its number, both applications did crash in the same manner at the same locations in the code. The reason is it tries to format a dial-string to look nice and crashes because there is no format string found.
Here’s my interpretation on what happens in Apple’s code does:
1. A SIM is inserted
2. MNC/MCC are read out
3. Symlinks are being created
/private/var/root/Libraries/Preferences/com.apple.carrier.plist/private/var/root/Libraries/Preferences/com.apple.operator.plist
will point to
/System/Library/Frameworks/CoreTelephony.framework/Support/carriers-name.plist
or if the carrier is not found to
/System/Library/Frameworks/CoreTelephony.framework/Support/UnknownCarrier.plist
There is also a symlink from the MNC/MCC codes to the carrier in the same directory.
/System/Library/Frameworks/CoreTelephony.framework/Support/<mnc><mcc>
also points to
/System/Library/Frameworks/CoreTelephony.framework/Support/carriers-name.plist
Now if you dial, the number formatting string is being pulled out by looking up MCC/MNC in
/System/Library/Frameworks/UIKit.framework/PhoneFormats/UIMobileCountryCodes.plist
to find the country code. Then the country code is being looked up in
/System/Library/Frameworks/UIKit.framework/PhoneFormats/UIPhoneFormats.plist
for the string formatting rules.
When UnknownCarrier.plist is being used because of unknown MNC/MCC, the lookup in UIMobileCountryCodes.plist seems to fail and no country is found and then the lookup in UIPhoneFormats.plist returns NULL which then makes the formatting routine crash.
Crash Fix
Create your own MCCMNC.plist file (see http://en.wikipedia.org/wiki/Mobile_Network_Code#International for known MNC/MCC values)
So for example for a Swisscom Mobile file you create
SwisscomMobile.plist
edit it to include the right APN’s etc. and then create a symlink 22801 to point to SwisscomMobile.plist
All this in directory /System/Library/Frameworks/CoreTelephony.framework/Support/ Then swap Simcard with other SIM (your unused AT&T SIM for example) and back. This will recreate the symlinks in /private/var/root/Library/Preferences. Now the code should remember 22801 as code and the mapping should properly work.
Source: Here