Problems since installation

Hi. Since installing this plugin I have had some unexpected behaviour of my site. I’m hoping someone here might have a suggestion to fix.
I have a photo gallery based website with a gallery index page.
Normally when I create new galleries, in the index, each one shows a thumbnail and short intro taken from the page it links to.
The page it links to has a full collection of photos and an extended version of the preview text from the index.
Since installing the plugin, the new gallery now shows all of the content on the index page.
I’ve tried to roll back to an earlier backup in cpanel installatron before the plugin was installed but now it is stuck with an error message saying “This is a failed install. It should be uninstalled.”

I’m not really sure what to do. Any help would be greatly appreciated.

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