Problem With The Stacks

So i downloaded the repaints of the default Double stacks and they wont install for some reason? Any help?
https://www.railworksamerica.com/forum/
https://www.railworksamerica.com/forum/viewtopic.php?f=29&t=7501
NS9030 wrote:So i downloaded the repaints of the default Double stacks and they wont install for some reason? Any help?