Sportspress - sort slider images

I have downloaded the sportspress theme and I am having some problems.

First, when I add images to the slider they work fine. But when I load the page later, the icon for the slider is with a red "x" on like the picture does not exist, though it works as intended on the front page.

But I can't sort which slider should come first, is it possible to change this? I want newest sliders to come first.

Hi!
This feature is not supported by our themes. The only thing you can do is to show your slides in random order. Unfortunately, I can't fix your slide icons in the dashboard. But you can use a debugging tool of wordpress to detect the problem. Please, read the following instruction: https://codex.wordpress.org/Debugging_in_WordPress