Does not want to simultaneously open the torrent file from..

[jonyrh]

Does not want to simultaneously open the torrent file from another tracker with the same content. Sorry for my English use a translator!

[Rolcol]

Yeah, since the torrent is the same, it will not allow duplicates. If you want the torrent to be shared on both trackers, change the infohash, or add the new tracker to the tracker list of the torrent already in Transmission.

[Marc31]

[...]
If you want the torrent to be shared on both trackers, change the infohash, or add the new tracker to the tracker list of the torrent already in Transmission.

Private trackers may frown. Best is to download (just) the .torrent file from the second tracker, have the Add Window point to the first tracker's completed files location and Verify them. If you don't get the full 100%, deselect the unverified ones for download first, then click Add.
This way at least, and more importantly, you will avoid the wrath of overly possessive admins.

best of luck, jonyrh,

[jonyrh]

Still does not download if there are different groups and different folders downloads...(((
PS: Thank you for your answers)))))