If there is no problem when the child theme is inactive, then either there is code inside it that causes this issue, or you have changed the name of the child theme. Changing the name may cause issues, try using the default child theme provided in the theme package.
It worked great until I updated Newspaper to 8.7. I was changing the name, but just tried it using all default settings, name, description and still get: “500 – Internal server error.
There is a problem with the resource you are looking for, and it cannot be displayed.”
Recent changes in the theme may no work with a child theme that has a different name than provided. The default child theme does not provide any errors, code in it may cause issues. So if the 500 error is displayed only with the child theme active, then there could be a problem with it. Try with the default child theme in the theme package, enter no code in it, see if the same thing happens.
Also check the theme system status, if there are sufficient resources
– https://forum.tagdiv.com/system-status-parameters-guide/
Maybe the hosting provider can check why exactly the 500 errors are happening, since it is a server error there could be logs to check.
The Revolution slider does not need to be activated, the bundled version does not require activation. You can import demo sliders and configure them to display posts
– https://forum.tagdiv.com/import-revolution-sliders-on-demos/