Offline dialer for android (Kitkat)
It's likely because most 3rd party apps as well as Google's own offering rely on Android's Text-to-Speech capability, which doesn't appear to be available offline on your device.

I understand you have set the offline language, but do just verify the following settings are set correctly:


  Go into the Settings app on your phone and navigate to Language &amp; input » Text-to-speech output. Tap on the Settings button next to Google Text-to-speech engine and then on Install voice data.


Ensure that the correct voice data is downloaded