Why can't I download and open pics sent as a text message on my Galaxy S3?

[AC Question]

Never had problem before switching from ATT to Straight talk. Could this be problem? I select download and it either cycles around without loading or I get a Currently unavailable. Try again later message. Mobile data is turned on. When I have Wi-Fi, mobile data turns itself off. HELP!

 

[Almeuit]

Ensure your APN settings are correct for your carrier and also ensure mobile data is on.