RAM may be an issue because I recently had a stick go bad and I’ve only got 8gb at the moment. I did fix the problem though. Apparently the new jpgs that I added were the same pixel depth but much larger in size (from 5mb up to 25mb). When I resaved them smaller, premiere started working again. This is the second time I’ve had issues with premiere that led back to large jpg still images being the problem. Very strange that premiere can handle massive hd videos but still images are too much for it.