Hey,
I got pretty stuck as well and I already wanted to give up on my fresh 10.8.2 Mountain Lion. This "unknown error" message by the App Store kept killing my nerves...
At least the App Store Login works now, so Apple still does not seem to have changed something "on their side"
iMessage still keeps bugging me with not being able to connect to the servers but that's not mission critical.
#Edit: According to this post, iMessage is currently not working, even on "real" macs:
http://www.insanelymac.com/forum/to...ed-bootplist-file-and-networkplist-file-help/
I kept booting from the Unibeast USB stick and applied all the tips described, however I couldn't login...
#Edit: Beside my tips I stumbled upon another good post dealing with the problem:
http://www.insanelymac.com/forum/topic/284684-icloudfacetimeappstore-login-errors/
What I did on my Mountain Lion after various attempts to get the Mac App Store login working was:
1. Open Finder right mouse click - open folder - /Library/Preferences/SystemConfiguration/
delete NetworkInterfaces.plist,
<b>delete preferences.plist </b>,
2. Open System Properties - Network - delete all adaptors like Ethernet, Firewire...
3. Re-Run MultiBeast
UserDSDT or DSDT-free Installation
Customization - System Definitions - MacBook Pro 8,1
This is quite important, my machine boots only with this one. I.E. iMac 12,1 does not work
(my hardware: Gigabyte Z68X-UD3H-B3, Bios F12 without UEFI, Intel Core i5 2500k, Intel HD3000, 8GB RAM, 1 onboard ethernet)
Customization - SSDT Options - Sandy Bridge Core i5
4. Download
search Google for sources...
EFIStudio 1.1
Chameleon Wizard
Tonymacx86 proper DSDT
5. Copy DSDT to /Extra
6. Start Chameleon Wizard
6a) SMBIOS
Open /Extra/smbios.plist
Edit
on the left select predefined symbioses, scroll up to MacBook 8,1
the data like week of manufacturing and on the right should be filled out
click save
6b) org.Chameleon.Boot
Ethernet Built In = yes
DSDT.aml = yes
/Extra/DSDT.aml
SMBIOS.plist = yes
/Extra/smbios.plist
Device Properties = yes
Now start EFIStudio1.1, Select Device, Ethernet
Add Device, Hex String to Clipboard
Paste to Chameleon Wizard below Device Properties using Paste Button on the right
I did not change the other default properties..
Click save
7) Reboot
Important:
Boot from hard disk using Chimera boot loader which should start if you select Boot from Harddisk!
8) NetworkInterfaces.plist must contain
<key>IOBuiltin</key>
<true/>
MAC OS X has to autodetect this, manually changing this value to true did not work for me. This seems to be dependant on booting from the hard disk...
Also look for model MacBook Pro 8,1 at the bottom
Do not paste this as I deleted my MAC-Adress....
PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Interfaces</key>
<array>
<dict>
<key>Active</key>
<true/>
<key>BSD Name</key>
<string>en0</string>
<key>IOBuiltin</key>
<true/>
<key>IOInterfaceType</key>
<integer>6</integer>
<key>IOInterfaceUnit</key>
<integer>0</integer>
<key>IOMACAddress</key>
<data>
'YourMacAdress
</data>
<key>IOPathMatch</key>
<string>IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/PEX6@1C,6/IOPCI2PCIBridge/ethernet@0/com_lnx2mac_RealtekRTL81xx/en0</string>
<key>SCNetworkInterfaceInfo</key>
<dict>
<key>UserDefinedName</key>
<string>Ethernet</string>
</dict>
<key>SCNetworkInterfaceType</key>
<string>Ethernet</string>
</dict>
<dict>
<key>Active</key>
<true/>
<key>BSD Name</key>
<string>fw0</string>
<key>IOBuiltin</key>
<true/>
<key>IOInterfaceType</key>
<integer>144</integer>
<key>IOInterfaceUnit</key>
<integer>0</integer>
<key>IOMACAddress</key>
<data>
'yourMACADress'
</data>
<key>IOPathMatch</key>
<string>IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/PEX3@1C,3/IOPCI2PCIBridge/pci-bridge@0/IOPCI2PCIBridge/pci1106,3044@2/AppleFWOHCI/IOFireWireController/IOFireWireLocalNode/IOFireWireIP/fw0</string>
<key>SCNetworkInterfaceInfo</key>
<dict>
<key>UserDefinedName</key>
<string>FireWire</string>
</dict>
<key>SCNetworkInterfaceType</key>
<string>FireWire</string>
</dict>
</array>
<key>Model</key>
<string>MacBookPro8,1</string>
</dict>
</plist>
9. Preferences.plist contains only one Model MacBook Pro 8,1; my old one contained various models, not sure if the App Store minds that...
10. App Store Login works