Originally Posted by NiLuJe
@linnx88: On a wild guess, I'd say you somehow ended up with newsfeed built in KF8 (AZW3) by Calibre... What's your default/preferred output format?
If it's AZW3, it should automatically fallback to MOBI, but if you have, in the MOBI output settings, the mobi file type option set to 'both' (mobi7+KF8) or 'new' (KF8) instead of 'old', I'm not quite sure what happens, and you may very well end up with a KF8 file. Which doesn't work for periodicals (and isn't supposed to, FWIW)
I just checked, and my mobi output is set to "old" format. So everything should be fine. I checked the news files on my Kindle and they're in "pobi" format. Which I take it is just like mobi, but for (p)ublications? Any other ideas? And like I mentioned above, they do open, but only through the sub-menu, otherwise you get an error the first time you try to open them. They open just fine with Calibre or Kindle-PC.