Well that was a bit of a fight but I made it!
I just upgraded from a Kindle 3G+WiFi to a PW3 only to find it didn't support Calibre Kindle Collections out of the box anymore.
So I had to downgrade the firmware (which nearly bricked the PW3 as it kept bootlooping then erroring out, but luckily putting the file in the root that tells it to factory restore did the trick).
Upgrade to 5.6.5.
Jailbreak it.
Install a patch so I don't lose the Jailbreak.
Install KUAL and MR Installer.
Upgrade to 5.8.1.
Install Collections Manager.
Find out Collections Manager isn't that great and remove it.
Install Python using MR Installer.
Install LibrarianSync using MRInstaller.
Wonder why LibrarianSync didn't install (head scratching ensued).
Get LibrarianSync from github then drop it into the extensions folder.
Run it, see the collections, do a little jig! (Well, maybe a quiet whoop and a well hidden fistpump).
All that because Amazon changed the collections format.
But alls well that ends well.
Thanks for a great app, totally got me out of a bind. 4000+ books are pain to put into collections manually!
