Deluge 1.3.12 is a fixes release that you must upgrade to, if you have not done so. There are following fixes in this release – GtkUI

Ubuntu, Linux Mint, Linux Lite, etc. Ubuntu already has Deluge in its official repositories but the update is not yet available in the official repository, but don’t worry you can add the official Deluge PPA to Update Deluge to 1.3.12.

Use the following commands to add PPA and then update the local list of repositories and then upgrade to Deluge 1.3.12.