dht disabled with magnet link

this solve the problem :

in tools options bittorrent privacy :
enable "use a different port for dht and bittorrent"
restart
even if it is the same port it'll work

but don't know why...

Hi. I can confirm this behavior with the windows client on win 7 home premium 64 bits.
Adding a magnet when qBittorrent is already running disables DHT for that torrent. Restarting qBittorrent re-enables DHT for all torrents.
Specifying a separate port for DHT helps overall but doesn't solve this issue.
This happens both with magnet links from Firefox 12 and magnet links from the built-in search. Links where provided by BT-Digg.

Problem seems to still exist with magnet links on 2.9.11. Neither enabling the "different port" option nor restarting helps.

Ok, I'll look into this, thanks.

DHT is not technically disabled for the torrent. Based on my testing, the UI wrongly reports that DHT is disabled for torrents without metadata (i.e. magnet links in initial state) but the number of DHT peers is correctly reported for the torrent (it is not 0) and the metadata does get downloaded. I have fixed the UI bug. However, I don't believe there is any DHT disabling. If you still think there is, please explain.

The fixed bug was a different problem entirely.
The DHT is actually being disabled — any magnet link is stalled until the program is restarted. This problem may be triggered by altering one of the settings (connection settings most likely, as I changed little else), because it doesn't seem to be present after a fresh install. Simply restoring settings to default values doesn't work though.

I had this issue for awhile and still had it after upgrading to 3.0.0. Comment #6 from the-user-11 is on to something. I'll copy/paste my description from another bug report https://bugs.launchpad.net/qbittorrent/+bug/1011037 :

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 "Any magnet link I click does not start properly in qBittorrent. It stays in a "stalled" status and info for seeds, peers, etc is not populated. The download does not start until I close qBittorrent and reopen it.

It may be related to the the following bug given comment #6:
https://bugs.launchpad.net/qbittorrent/+bug/987340

Win7 x64
qBittorrent 3.0.0"
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Comment #6 (the-user-11) here may be on to something, because I uninstalled, then deleted the two qBittorrent folders in my User directory to create a clean install of 3.0.0. Now magnet link torrents start correctly again. I set my connection settings up again and still working fine. Maybe the issue was an interaction between a setting file from a previous version. My previous install was consistently upgraded from around qBittorrent 2.8.

Update: The issue eventually came back. Magnet links require a client restart once again. No settings were changed.