I have discovered some partial downloads months after the fact and could not figure how to open then either. Kay
I found the design for you and added it to your other message in Q&A.
Also, be aware that it would be a zipped file. You should be able to right click the file folder and un-compress the files.
Crafter2243 is correct. The download may have been interrupted or incomplete. If you paid for it -- it will still be in your download folder.
If you paid for it you can go into your download and do it again. I have given you a link to the design so you know which one it is.
A partial download is usually a corrupt file. It has many reasons why that can happen. I do not think it is a new window issue.