you really should add some more information. What are you trying to archieve, what did you do and what did you expect it to do.
I have a one page theme called ZIGZAG.
In the slider options I uploaded an image and saved it. However, the image does not pop up in the slider.
in the list with the images (media) the images seem not to be activated. I tried to link them to a page, but it does not work. They are not displayed on the page.
did you connect the slider to a page?
Did you specify that the image is included in the slider?
I’m sorry but as you appear to be using a commercial theme, you need to seek support from the theme’s developer/vendor. We do not support commercial products here.