CT Instagram not displaying images

I've CT Instagram set up with Rockstar Pro - a few months ago, without any changes by myself the widget stopped displaying images, though it was still picking up and publishing the text of Instagram posts from the relevant account, so it's not the feed itself. I've tried the following:

• Updated rockstar pro theme
• removed all custom css relating to the widget
• tested the widget with another Instagram account (same thing)
I cannot update the CT Instagram widget itself, it being wrapped in the Rockstar Pro theme. I don't really want to try the new CT Instgram plugin or similar unless 100% necessary as this is part of a paid-for theme, DID work and should still work!