v3.3.16 changelog:
BUGFIX: Better memory footprint when using libtorrent 1.1.x. The cache is turned off by default(0 (disabled) value in the settings). The value -1 (auto) makes it use 1/8 of your RAM. (sledgehammer999)
BUGFIX: Skip user input events when adding torrent. Closes #7327. (glassez)
BUGFIX: Avoid memory leak in the speed graph. (Chocobo1)
WEBUI: Fix validating wrong header field. X-Forwarded-Host is a foreign proxy setting, it isn't the same as qbt's local setting and thus it makes no sense to verify it. Closes #7311. (Chocobo1)
WINDOWS: Fix connection problems when a specific interface/ip is configured. (sledgehammer999)
WINDOWS: Disable skipping of loopback interfaces. This fixes the absence of VPN tunnel interfaces under Windows and works around the QTBUG-32349. Fixes #7291. (Evengard)
WINDOWS: The installer detects the 64bit running process too. (vlakoff)