Keep getting the response "No Subject" on group text from voice assistant, why?

[WPCentral Question]

My carrier is T-Mobile. Had the problem recently with my HTC Radar and now having the same problem using Cortana.

 

[several potatos]

The problem is that MMS messages get titled 'no subject' until you manually download the message content. Sadly, nothing you can do about it. It's a known issue on a lot of T-Mo phones.