editing free assets ((almost) identical twins)

I'm writing a course about observing, better looking etc. I use storytelling: the sisters Dora and Flora, identical twins, take you through the course.

I would like to use the free assets. I've found them on my (dutch) computer in C//gebruikers/openbaar/openbare documenten/adobe/e-learning assets/characters_9_0/assets/assets/high

The problem is that I can't open them. I want to give Dora and Flora a different colour shirt, so I've to edit the images a little bit.

I cán open an image i downloaded months ago, but not the images i downloaded recently. Our system engineer can't find any safety issue that causes this problem.

In the appendix I send a printscreen.

Why is it not possible (anymore) to open the images? You see the locks by Herlinda, Herlinda and Rachel. But not by Angela.

Is there a way to edit the free assets a little bit? Anyone any idea??

Thanks for your help!

Bernice