As promised to @Bmetamax there goes a bit of explanation of the contents of the Tribler state directory:
The .Tribler directory keeps all the state related of Tribler for your user and it is kept across reinstalls. This means that if Tribler is crashing for you due to some file in the state directory being corrupted, reinstalling Tribler won’t make any difference.
This folder can be found on the root of your home directory on Linux
~/.Tribler/ and on your user’s
%APPDATA%\roaming directory (If you don’t know how to get there, just open the start menu and copy-paste that on the search box.
Description of each file/directory and its contents:
This directory contains the data generated by the anontunnel experiment that was embedded in older versions of Tribler, it can be safely deleted.
This is the LevelDB store that contains all the metadata collected for the torrents discovered on the Tribler network.
These used to be collected for the randomly discovered torrents, which meant that all sorts of nasty stuff could be found there. Metadata collecting was temporarily disabled on the last release while we worked on a better solution, and Tribler 6.6 will only fetch metadata for torrents found in channels you are subscribed to and only if generated by the channel owner.
This is the LevelDB store that contains all the torrent files collected either randomly, from your searches, from subscribed channels and the ones added to your channel.
These torrents are used to get instant results when searching and to send to other peers with similar tastes.
This directory contains INI-like persistence files for all the downloads, each is named after the infohash of the torrent it holds information for.
This file holds the private cryptographic key used to proof your identity on the network.
It’s used to sign all the messages generated by you, including the ones that compose your channel. Lose this key and you will lose ownership of your channel.
This file holds the public part of your key. Which can be used to verify that any given message was signed with your private key and thus originates from you.
INI-like file that contains all the Tribler core settings.
DHT state cache file, can be deleted safely and will be regenerated.
Leftover dir, used to be used as a temporary dir when fetching torrents from the DHT, but now we use a real temporary dir.
Will be removed in the future.
Plaintext peer cache table, used to accelerate the bootstrap process when starting Tribler in addition to the official Dispersy trackers.
This means that even if for whatever reason all our trackers get disconnected, you will be able to bootstrap the network as far as some of the peers you contacted in the past are still online.
DHT log file.
This directory contains all the sqlite databases used to store all the dispersy messages, channels, search info, etc.
INI-like config file that contains download and gui-related settings such as window placement and size.
That’s the basic stuff. Let me know if you are interested in more in depth description of any given file and I’ll do my best to update the post.