IMac Message not allowing preference or account changes. These options are "greyed" out.

Question

How can I get Message to allow changes to preferences and/or accounts?  These are both greyed out and can't be accessed.  My Message icon show that I have messages, but the messages do not show when icon is selected.  Everything I have read says to go to preferences, but I menu doesn't allow it.

Answer 1

Hi,
You will notice that in System Preferences > iCloud there is also no listing of iTunes, App Store, Game Center or FaceTime that may also be using the same ID.
iCloud is a service and mostly shows the items that can be Synced to other Macs using the same ID or the iOS devices doing the same.
So PhotoStream is on the Net (in the cloud) so to speak and not on you iPhone but you can show the pics (or at least the last 1000) to people on your iPhone.
Similarly you Contacts only have to changed in one place and will change on all devices
iMessages uses an Apple ID.  It does seem it also has to be an iCloud one (at least since Mavericks and Messages 8.0)
As Yahoo ID are email accounts it will also appear in System Preferences > Internet Accounts and give you the option to have it active in Messages
Whilst it might be your Apple ID and you might use it for the iMessages account you can also use it for an Yahoo Account in Messages and use the Yahoo Instant Messages service.
(I have loads)
It should work like this:-
Enter the (Apple) ID you want to use in the iMessages account along with the password you might use for that email ID at Apple (presuming the Apple use the the Yahoo use have different passwords to the ID).
The iMessages Receive section (Messages > Preferences > Accounts) should show just that Apple ID at present.
Then you Enable the Messages app on the iPhone.
Once the Number has verified you can add other Send And Receive IDs.  The first tend to be the Apple ID you used on the Mac.
If you restart the Mac version you should get a pop up telling you what IDs (Apple ID and iPhone number) the iPhone is using.
You Have to Accept this Pop up to have the Mac add the iPhone Number to it's Receive At list (And to the Start Conversation From drop down).
If this was not accepted remove the Apple ID from the iPhone (it is worth double checking the iPhone can still send to the Apple ID)
Place th iPhone in Airplane mode for a few minute to Break with Server.
The "restart" the iPhone and the App.
If the iPhone number is verified then Add the Apple ID
Restart the Mac version (It makes the pop ups appear just a little quicker)
Accept the pop ups.
9:08 pm      Thursday; October 30, 2014
​  iMac 2.5Ghz i5 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