title_body: collection shows as empty and refuses to populate -- not syncing properly I had a few collections on the Amazon Kindle web interface populated with books purchased through Amazon, readable through the web reader.  However, I wasn't able get my Kindle to sync with the cloud so that they even showed as available until resetting the Kindle to factory defaults.
  
  Might this be related to pending deliveries?  Or, the download queue?
  
  I confirmed that books were being downloaded, that there was sufficient free space.  And, yet, the Kindle showed the collections as empty until it was reset to factory defaults.
  
  I even selected the items and attempted to deliver them to the specific device, which was reported as being successful.  However, the pending deliveries remained unchanged.
  
  It was as if the items weren't showing due to incompatibility with the Kindle reader -- and yet, clearly, they were compatible.  How do I know that the items are compatible?  Because, by resetting the Kindle to factory defaults the content loads.  But, and here's the key point:  only after resetting the Kindle.
  
  Therefore, the problem lies with the Kindle itself, or at least how it syncs -- and not with the content.  Yet, it seems like the content is incompatible.
  
  see also:
  
  Kindle collections and books not synching properly
  
  That salient point being that other users report that what shows on Manage Your Content, the web interface, does not get similarly reflected on a Kindle e-book device.  What I describe is a little different, but, probably, the result of the same underlying bug.
upvoted_answer: I think I see the problem (or one problem at least). 
  
  I have a massive set of collections on the kindle app for android. (Like 50 collections holding 2000 or more ebooks). 
  
  But when I install the Kindle for PC app for my Windows desktop, it does not let me import the organized collections from the Kindle app for android. When I use the Kindle for PC app, there is an IMPORT COLLECTIONS option, but it prompts me to choose between two older devices instead of my current android devices. These older devices used a type of collections which is different from the current one. 
  
  If I create a NEW collection on Kindle for PC and add ebooks to it, this new collection does not appear on my android app or even on Manage Your Content and Devices page. 
  
  You would assume that collections propagate to all Kindle platforms, but what I'm seeing now is that any collections you create on Kindle for PC will not be propagated onto your other reading systems. As you see, you can still access your ebooks, but you can't use the collections from your other devices. 
  
  You're not doing it wrong; the Windows program is just using an incompatible kind of collection system. 
  
  On the plus side, any collections you make on Kindle for PC are just for that computer -- and nothing else. (Just to be safe, I would create only a small number of collections on Kindle for PC). I have verified that annotations on the Kindle for PC propagate (albeit slowly) to other devices.