HOW TO FIX MESSAGES APP
work in progress-subject to change
This is only for those of you who are running Mountain Lion and getting this error since the Messages Beta for Lion ended on 12/14/12, but can still sign into other services like iCloud, App Store, etc.
Messages-Not SignIn.jpg 40.69K 308 downloads
To fix this, we need an added value to the NVRAM which as of the time of this writing, can only be done by using the latest revision (r980) of boot loader by Slice, dmazar and others: Clover.png 45.83K 773 downloads
To get the most recent installer package, we"ll use the tool created by STLVNUB: "Clover Grower" which can be downloaded here. You'll need Xcode's Command Line Tools installed, available for download in Xcode's preferences. The full list of instructions and options can be found here. Highly recommend reading them since every person's setup is different and there are many additional features you may want to explore. Only the basics here.
Once you've downloaded Clover Grower, open Terminal.app from /Application/Utilities/Terminal.app. From your downloaded Clover Grower, drag and drop CloverGrower.command into terminal window and hit enter. Follow the prompts and enter password, Yes, etc. when asked. I recommend using all default settings unless you know what your doing. The process may take a little while as additional tools to compile are installed by the script. Once it's all done you should now have a folder with the package installer in it looking like this:
CloverGrowerV4.9.jpg 110.34K 1142 downloads
Next prepare a USB thumb drive to install it onto. Use Disk Utility and format it as FAT32 with a MBR partition scheme. You can install the boot loader to your main hard drive later once your sure it all works and are comfortable with the configuration.
Run the Clover package installer, leaving all settings as default except choose your thumb drive as the install location.
Install Clover v2 rL980 x32 x64 EFI bootloader.jpg 65.77K 742 downloads fat.jpg 72.25K 513 downloads
Once the install is complete navigate to your new Clover USB drive and open the config.plist with text editor (RT Click and "Open With")
FAT32files.jpg 94.89K 1567 downloads
This plist is like org.chameleon.Boot.plist and smbios.plist all in one file. Some options are the same, some are similar but have different names, and some are new for added config ability. This is where some system specific changes maybe needed, but first try simple leaving everything as is, and will only add info from our current smbios and what's needed for messages fix. Copy all info from your smbios into config.plist, and then you will need to change the names of the values inside each <key></key> to match the new format. Here is how they need to be named in Clover:
SMBIOS.png 100.71K 2811 downloads
Additional examples can be found in /EFI/doc/ inside Clover drive.
For UEFI boot and additional Graphics config, follow dmazar's instructions here
For the Message part, first get your current serial which is in the smbios you just copied, and can also be found in system information:
Mac Pro-Serial.jpg 55.98K 2697 downloads
Now we add a new entry to config.plist that includes that 11 digit serial #, but we need to append 6 more digits onto it to make it a 17 digit #. So for example RM9MYSERIAL becomes RM9MYSERIAL234567 and the entry looks like this:
<key>RtVariables</key> <dict> <key>MLB</key> <string>RM916W05EEP3574PC</string> </dict>
In the image below you can see inserted into the list with some of the entry before and after visible to give an idea how it should look.
This is mine for my own PC, not yours, it's for frame of reference on how the code is inserted and should not to be copied in full if you want anything to work!
config.plist2.jpg 77.15K 1607 downloads
If you use a patched DSDT, copy it to the root of your main OSX drive.
Please, please, please read all the instructions for Clover here before asking any Clover related questions!
Edit or maybe Warning: One note, a few people have had message saying "account locked, call customer service" either right away or even after a successful login and a reboot. Not sure the cause, but I recommend rebooting twice before trying to log into Messages incase there are nvram values such as platform-uuid that if you are not specifying them in config.plist, Clover will set them at shutdown to be applied on the next reboot, which would then be the second time your booting using Clover.--Further reports on this have indicated success after a credit card has been tied to appleID account through the appstore, or when a small $1 app is purchased.
Credits: The testing, brainstorming and collaborating involved was an unprecedented (in recent history) effort by the entire community, with valued efforts by too many people to list, but a special thank you to ElNono and flux84 for putting the final pieces together, to Slice for Clover and dmazar for pushing and update so quickly! Great work everyone!!!