Something very wrong... Can't figure out

Would anyone have a clue as to why an ebook I updated and uploaded to Amazon works on two of my friends e reader devices, yet won’t work on my Ipad or computer? According to the email confirmation, Amazon says it’s published. On my comp it says Download Failed (I downloaded the sample). On my Ipad it says I need to update my kindle version for my Ipad, which I did several times, but it keeps saying the same thing. I’ve written 4 books using Scrivener, and this is the first time it’s given me problems…

Heck, it might not be Scrivener giving me the problem. I can’t figure out why it would work on 2 other e reader devices and not on either my comp or Ipad.

This could be related to the file name.
You may already have a file with the same file name on your PC and iPad and the download program can’t overwrite it.