Sorry for a lot of noise ... I tried to play more with click-to-pan mode. It worked, but when I *additionally* enabled Click to Play mode - sometimes Compositor window just hang. If I select 'Protect video' mode in compositor - then Click-to-Play mode works as expected. Basically, try to 0) set cursor to evry beginning of timeline (home) 1) load movie into CinGG 2) in Compositor window DISABLE both Zoom mode and Click-to-play 3) Then Enable Zoom mode (marked F2) 4) Then enable click-to-play 5) Click somewhere near low part of video in compositor, around horizontal zoom scrollbar 6) It should hang Not sure if dump AFTER I made forced (Ctrl-C) quit actually useful? LANG=C cin Cinelerra Infinity - built: Feb 28 2020 20:17:26 git://git.cinelerra-gg.org/goodguy/cinelerra.git (c) 2006-2019 Heroine Virtual Ltd. by Adam Williams 2007-2020 mods for Cinelerra-GG by W.P.Morrow aka goodguy Cinelerra is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. There is absolutely no warranty for Cinelerra. ^C** intr at 0xf7b24421 in pid 2303, tid 2303 writing debug data to /tmp/cinelerra_2303.dmp lock_items: 17 lock_frees: 11 ** dump complete ^C