[Plugin: The Piecemaker 2] Does Not Work as Advertised. Please Help.

Donwloaded zip file for WordPress. Copied the piecemaker folder to the wp-content/plugins folder. Activated in WP per instructions. When I went to upload assets I got a permissions error. I found an article that told me to create folders piecemakers and piecemaker-images in the wp-includes folder and to set permissions to “777” (whatever the heck that means. I gave everyone read and write permission. I was then able to upload assets without error. BUT the files never showed up in the asset list. It says, “There are currently no files.” I can create a piecemaker, but there are no slides to add. What gives?

https://www.ads-software.com/extend/plugins/the-piecemaker-image-rotator/