I have fresh installation of Alfresco Community 5.0.a-2 (64-bit) running on Ubuntu 14.04. When I open User Profile I do not see Language page (see screenshot). Any idea why it is missing and what should I do to get it back?
I am not sure what exactly you do expect, but as far as I know, there never was a language page in Alfresco Share. You set language via your browser settings and not in the user interface.
Are you talking about the language you can set from alfresco explorer (See attachment - User_Profile_Alf_Explorer.png) ? I don't think you will find it in Alf.Share.
This video demonstrates Alfresco One in the cloud. Are you using cloud ? Can you once refer to the alfresco documentation for your version ? It might not provide the language feature you are looking for. You may need customization to achieve it.