I can't log in to Messages or FaceTime with my iCloud account.

Hi,

This issue does seem to vary from person to person and cover some quite odd items in the process.

9:50 pm Thursday; November 7, 2013

 iMac 2.5Ghz 5i 2011 (Mavericks 10.9)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad

Hi Ralph,

I have tried everything before and after the clean install of 10.9. My next step will be to downgrade to 10.8

Understood.

8:14 pm Friday; November 8, 2013

 iMac 2.5Ghz 5i 2011 (Mavericks 10.9)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad

Hello Ralf,

You seem to know well how to solve this problem.

My Macpro has the same issue. I made an upgrade from Leopard to OSX and Imessage refused to login (I test several apple account and several internet network)

I had in the past a change of my motherboard and effectively when I look into the Information system the serial number is missing (it is written "Not Available" ).

Do you know how to "written" the serial number. Does I really need to go on an apple store to do it (I am in France)?

Many thanks for your answer,

Cheers,

Harpa

HI,

I have been Posting that people should use an Apple Store or Apple Authorised Service Provider (AASP).

I would have to think long and hard about using any other method.

However I have seen posts here about an App that can be downloaded and will do this (it needs very careful typing as you can only do it once).

I am not sure of the apps name as I would be unlikely to use it myself.

I do understand though that not everyone is within reach of an Apple Store or a Service Provider.

I would start by searching the other threads mentioned in the "More Like This", box top right.

8:14 pm Saturday; November 9, 2013

 iMac 2.5Ghz 5i 2011 (Mavericks 10.9)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad

Hi,

I solved my problem with the Blank Board Serializer, v.3T106, part number 693-6430.

Works on a MacPro end 2008 2,8 Intel core 2 Duo.

You can look for a file named blank board serializer 3t106 063-7137.zip

Previsouly I should have downloaded a bad version of this tool.

Many thanks to Ralf and the community

Harpa

Hi,

In Messages > Preference > Viewing what Font are you using to send out going text messages ?

Is this Font Enabled in the Font Book ?

7:57 pm Tuesday; November 12, 2013

 iMac 2.5Ghz 5i 2011 (Mavericks 10.9)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad

It's Ralph, but thanks.

8:34 pm Tuesday; November 12, 2013

 iMac 2.5Ghz 5i 2011 (Mavericks 10.9)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad

How does one reset the keychain? Thanks. update: never mind, I found the answer elsewhere in this thread: http://support.apple.com/kb/TS1544?viewlocale=en_US&locale=en_US

Also see this: http://rogersm.net/icloud-problems-mountain-lion-serial-number

Thank you for this solution! I tried resetting the keychain and that did not solve my problem. However, Blank Board Serializer did work, yay, finally! Again, see the link below for instructions. Follow them carefully there are no redos! If you are cautious, then take your machine to Apple and let them do it.

http://rogersm.net/icloud-problems-mountain-lion-serial-number

Thanks for your suggestion, I did have my logic board replaced two years ago and it appears that the technician did not reinstall the serial number.

This was my problem! Unbelieveable... anyway I found the utility online (I really did not want to cart my 50lb Mac Pro back down to the Apple Store) and it worked perfectly.