I don't see my contact's names on message anymore, why?

Question

I've been using message for a while and it has always been working fine.
Once I messed up with my internet accounts and eventually I fixed it.
Now, even though message is sync with my iphone and I see incoming messages on both devices, I don't see my contact's name on my IMac.
On my Iphone continue to work just fine, but on the Imac I can't see their names...ggrrrrrr!!
Does anybody know what might have happened?
thank you all,
Lorenzo

Answer 1

Please try each of the following steps that you haven't already tried.
Step 1
You may need to synchronize contacts between the Mac and your other devices. One way to do that is via iCloud. On the Mac, open the iCloud preference pane and sign in if you haven't already done so. Check the box marked Contacts. Do the equivalent on your mobile device(s).
Make sure that your contact accounts are enabled in the Accounts tab of the Contacts preferences window.
Step 2
If you use a messaging service other than iMessage, then from the Messages menu bar, select
          View ▹ Buddy Names ▹ Show Full Names (or Show Short Names)
Step 3
From the menu bar, select
           ▹ System Preferences... ▹ Language & Region
From the Region menu in the window, select one of the preset regions. If one is already selected, choose a different one, then change it back. Close the preference pane. Quit and relaunch Messages.
If you still have the problem after taking those steps, post your results.