Flynax classified software small custimization

I have a website [login to view URL], that uses a classifieds platform from flynax.com. My platform had a small custimization in the past, now i need to upgrade and change the template, I already have the new template downloaded. Once the new template is installed correctly, I will be able to select it from the admin dashboard as in image 1 Image 2 is from the file manager in the cpanel. I was able to install the file, but when I selected the template recently added, the site gives an error. Thanks