Do you have a link to that mod? The Nexus site is giving me zero results, even if I just search for 'container' or 'background'.
What is the path to the mod? Hold Shift when right clicking file(s)/folder(s) and you will get an option to copy the full path(s) to the clipboard.
Mods installed to the install folder would not show up in the mod list, but should override the original file(s) if they are in the right place in the Data folder.
