The reason why you are unable to receive picture messages on your HTC EVO 3D phone could be because you have turned off mobile data. The HTC EVO 3D phone would not receive any picture messages with the mobile data off. It the problem still persist, then you should have a technician fix the phone.
It has something to do with the phone being flashed. I have Cricket for my phone carrier. My phone is an HTC EVO that was originally with Sprint. My phone guy had to download some special messaging app so that I could send/receive pictures.