I just looked over your account. You should not have any problems at all.
Please try again and if you are still having problems, please post what the message is that you get and I will do what I can to correct it.
I haven't looked over all the models here, but paper models tend to be available mostly in one of these formats: PDF, JPG or Pepakura. For PDF you need a free viewer such as Adobe Acrobat Reader, though I use Foxit Reader, which does about the same thing. JPG images come up in Windows Paint and many other image viewers. Pepakura files (PDO) require you to download and install the free Pepakura file viewer from the Tamasoft's website: http://www.tamasoft.co.jp/pepakura-en/download/viewer.html
Download and Install this.If you are on a Mac,you cannot use Pepakura viewer or .PDO files. That's Apple's fault.
Use the search function to find the answer to these questions. You have been here long enough.
Also,POST an INTRODUCTION post, as you haven't and we do not know who you are. This is a requirement. Make your next post an Introduction. You will find people more willing to help you if they know who you are. O.K.?
I will be looking for that post, so we can great you and meet you!