Why did I get a .zip file instead of .epub?

We've found that a few Windows machines take our .epubs and, inexplicably, rename the .epub file extension .zip. None of our ebook files should come to you in .zip format. If you're seeing a .zip file, it's an error.

The easiest way to fix this is by renaming your file from XXXX.zip back to XXXX.epub. Then make sure you open the .epub file with an epub-compatible software or device.