Slider item render issue.

You probably installed the theme manually and not using Composer. So, the theme is in folder /themes/black-hole. If installed properly with Composer the theme will rest at /themes/contrib/black_hole.

You have two options:
1) Install the theme at /themes/contrib/black_hole, or better
2) Change all slides paths to: "/themes/black_hole/_custom/sliderimg/IMAGE.jpg

@Florian , i have installed the theme using composer but getting same issue.

hi @Gautam_105@
All ready fixed i am not getting error along with i shared screen shot.

You should have saved the configuration.
This behavior is by design. It allows you to use any images hosted on any server.