Assume that you install Chinese language packs for Microsoft Exchange Server 2013 Unified Messaging (UM) role on a Windows Server 2012 R2 server. When you call the UM subscriber access number of a UM dial plan to access your mailbox, no greeting is played.
This issue occurs because Chinese language packs are incompatible with Windows Server 2012 R2. The incompatibility exists in the text-to-speech (TTS) engine that is controlled by Microsoft Speech Platform runtime which is a prerequisite for Exchange UM 2013.
Note The TTS engine reads email, voice mail, and calendar items and plays the menu prompts for callers.
To work around this issue, set the default language of dial plan to English. If you have to use Chinese Language pack, the only supported option is to downgrade the operating system of Exchange Server 2013 to Windows Server 2012 or Windows Server 2008.